Acquisitions - Fair Values of Assets Acquired and Liabilities Assumed at Date of Closing - SAT (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Sep. 26, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 220,163	$ 165,861		$ 129,888
SAT Technology, Inc. ("SAT") [Member]
Business Acquisition [Line Items]
Current assets			$ 1,679
Property and equipment			10
Goodwill			1,733
Intangible – finite life			840
Intangible – indefinite life			260
Total assets acquired			4,522
Current liabilities assumed			(1,847)
Deferred tax liabilities			(275)
Net assets acquired			$ 2,400