Fair Value Measurements - Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Beginning balance, acquisition earnout accruals	$ 12,033
Earnout payments	7,461	$ 5,496
Ending balance, acquisition earnout accruals	6,197
Fair Value, Inputs, Level 3 [Member]
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Beginning balance, acquisition earnout accruals	12,033
Ending balance, acquisition earnout accruals	6,197
Fair Value, Inputs, Level 3 [Member] | Acquisition Earnout Accruals [Member]
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Beginning balance, acquisition earnout accruals	12,033
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Business Combination, Acquisition Earnout, Fair Value	1,454
Earnout Accretion Fair Value Disclosure	(558)
Earnout Payments Fair Value Disclosure	7,461
Foreign currency translation	387
Ending balance, acquisition earnout accruals	$ 6,197