Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Dec. 31, 2015
Monte Carlo Simulation Valuation Model
Liabilities:
Undiscounted maximum payment under the contingent consideration arrangements		$ 7,900
Increase in fair value of contingent consideration related to changes in foreign currency		100
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring [Member]
Assets:
Short-term investments	[1]	42,952	$ 42,994
Total		42,952	42,994
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring [Member]
Liabilities:
Contingent consideration	[2]	2,820	2,695
Total		$ 2,820	$ 2,695

[1] Short-term investments in the accompanying consolidated balance sheets are six-month U.S. Treasury Bills. The fair values of these assets are based on Level 1 inputs in the fair value hierarchy.

[2] Contingent consideration liability represents arrangements to pay the former owners of certain companies we acquired. The undiscounted maximum payment under the arrangements was $7.9 million at the end of the first quarter of 2016, based on future revenues, gross profits and certain milestones. We estimated the fair value of the contingent consideration using a Monte Carlo Simulation, which is based on significant inputs, primarily forecasted future results of the acquired businesses, not observable in the market, and thus represents a Level 3 measure. The increase in the fair value of the contingent consideration from December 31, 2015 to March 31, 2016 of $0.1 million related to changes in foreign currency.