Annual report pursuant to Section 13 and 15(d)

Significant Customers (Details)

v2.4.1.9
Significant Customers (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Revenue, Major Customer [Line Items]    
Revenue $ 119,935us-gaap_Revenues $ 146,534us-gaap_Revenues
Entity-Wide Revenue, Major Customer, Percentage 69.70%us-gaap_ConcentrationRiskPercentage1 67.40%us-gaap_ConcentrationRiskPercentage1
Entity-Wide Receivables, Major Customer, Percentage 51.50%pdii_EntityWideReceivablesMajorCustomerPercentage 86.00%pdii_EntityWideReceivablesMajorCustomerPercentage
Customer A [Member]    
Revenue, Major Customer [Line Items]    
Receivables from Customers 7,341us-gaap_ReceivablesFromCustomers
/ us-gaap_MajorCustomersAxis
= pdii_CustomerMember
9,153us-gaap_ReceivablesFromCustomers
/ us-gaap_MajorCustomersAxis
= pdii_CustomerMember
Revenue 57,039us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= pdii_CustomerMember
70,827us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= pdii_CustomerMember
Customer E [Member]    
Revenue, Major Customer [Line Items]    
Revenue $ 26,825us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= pdii_CustomerEMember
$ 27,976us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= pdii_CustomerEMember
Minimum [Member]    
Revenue, Major Customer [Line Items]    
Entity-Wide Revenue, Major Customer, Percentage 10.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_RangeAxis
= us-gaap_MinimumMember