Change in the Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Goodwill [Roll Forward]
Balance, December 31, 2014	$ 825,038
Acquisitions	274,364
Foreign currency translation	(1,823)
Balance, June 30, 2015	$ 1,097,579