Significant Customers & Concentration of Credit Risk (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Concentration Risk [Line Items]
Unbilled accounts receivable		$ 99,588		$ 105,549
Single Customer
Concentration Risk [Line Items]
Unbilled accounts receivable		16,400
Single Financial Services Customer
Concentration Risk [Line Items]
Unbilled accounts receivable		$ 24,900
Revenue | Single Customer
Concentration Risk [Line Items]
Concentration risk percentage	14.00%	14.00%
Revenue | Single Financial Services Customer
Concentration Risk [Line Items]
Concentration risk percentage		13.00%	15.00%
Revenue | Automotive Industry
Concentration Risk [Line Items]
Concentration risk percentage		23.00%	22.00%
Revenue | Financial & Insurance Industry
Concentration Risk [Line Items]
Concentration risk percentage		19.00%	21.00%
Accounts Receivable | Single Customer
Concentration Risk [Line Items]
Concentration risk percentage		16.00%
Accounts Receivable | Single Financial Services Customer
Concentration Risk [Line Items]
Concentration risk percentage		17.00%