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Stock-Based Compensation (Weighted Average Assumptions) (Details) (USD $)
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3 Months Ended | 12 Months Ended | |
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Mar. 31, 2014
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Dec. 31, 2014
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Dec. 31, 2013
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 3.76us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue | ||
| Consecutive trading days | 60 days | ||
| Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | $ 4.33us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice | ||
| Risk-free interest rate | 0.75%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate | 0.33%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate | |
| Expected life | 3 years 6 months | 3 years 6 months | |
| Expected volatility | 48.15%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate | 49.80%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate | |
| Performance Shares [Member] | Chief Executive Officer [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Performance Shares Target Premium |
50.00%pdii_PerformanceSharesTargetPremium / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Performance Shares [Member] | Performance Shares First Tranche [Domain] | Chief Executive Officer [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |
36,496us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesFirstTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Average stock price, performance shares |
7.65pdii_Averagestockpriceperformanceshares / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesFirstTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Performance Shares [Member] | Performance Shares Second Tranche [Domain] | Chief Executive Officer [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |
64,460us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesSecondTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Average stock price, performance shares |
10.20pdii_Averagestockpriceperformanceshares / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesSecondTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Expected life | 5 years | ||
| Performance Shares [Member] | Performance Shares Final Tranche [Domain] | Chief Executive Officer [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |
87,209us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesFinalTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Average stock price, performance shares |
15.30pdii_Averagestockpriceperformanceshares / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_StatementEquityComponentsAxis = pdii_PerformanceSharesFinalTrancheDomain / us-gaap_TitleOfIndividualAxis = us-gaap_ChiefExecutiveOfficerMember |
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| Expected life | 5 years | ||
| X | ||||||||||
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- Definition
The average stock price over a period of time used to determine if performance shares criteria are met. No definition available.
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- Definition
Period of time over which performance criteria have to be met to trigger the release of performance shares. No definition available.
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- Definition
Minimum percentage premium above grant price where performance targets are set No definition available.
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- Definition
The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. No definition available.
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- Details
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