Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Fair Value, Inputs, Level 1
Assets:
Short-term investments	[1]	$ 42,975	$ 42,994
Total		42,975	42,994
Fair Value, Inputs, Level 3
Liabilities:
Contingent consideration	[2]	2,692	2,695
Total		$ 2,692	$ 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 second 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. In April 2016, the company paid $0.1 million as part of this arrangement. The remaining change in the fair value of the contingent consideration from December 31, 2015 to June 30, 2016 is related to changes in foreign currency.