Fair Value Measurements - Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2013		$ 24,287
Balance at December 31, 2014	22,050	24,287
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2013	(13,437)
Realized / unrealized gains	(336)
Earnout accretion	(1,854)
Earnout payments	3,390
Foreign currency translation	(427)
Balance at December 31, 2014	(12,664)
Significant Unobservable Inputs (Level 3) [Member] | Warrants and Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2013	616
Realized / unrealized gains	(336)
Balance at December 31, 2014	280
Significant Unobservable Inputs (Level 3) [Member] | Acquisition Earnout Accruals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2013	(14,053)
Earnout accretion	(1,854)
Earnout payments	3,390
Foreign currency translation	(427)
Balance at December 31, 2014	$ (12,944)