Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended			12 Months Ended
	Jan. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($) revenue_source	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred tax liabilities			$ 29,777		$ 32,386	$ 29,777
Principles of Consolidation
Cash paid for purchase of noncontrolling interests in foreign subsidiaries		$ 5,000	700	$ 800	$ 4,992	708	$ 800
Revenue Recognition
Number of primary sources of revenue from consulting services (revenue source) | revenue_source					3
Expected period for collection of unbilled accounts receivable (years)					1 year
Unamortized debt fees			1,340		$ 770	1,340
Prepaid Expenses and Other Current Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred tax assets			1,700			1,700
Accrued Liabilities
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred tax liabilities			$ 400			$ 400
Pennsylvania Turnpike Commission v. Ciber, Inc., and Dennis Miller
Condensed Balance Sheet Statements, Captions [Line Items]
Damages alleged by PTC	$ 38,000