Product and Geographic Sales Information - Summary of Revenues by Geography (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 300,888	$ 280,894	$ 212,768	$ 205,735	$ 200,731	$ 192,598	$ 188,722	$ 185,810	$ 1,000,285	$ 767,861	$ 712,702
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									682,293	514,803	466,670
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									55,562	63,037	60,980
Americas, Excluding United States and Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									22,186	15,745	16,760
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									107,081	99,163	97,079
Europe, Excluding United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									68,347	49,929	51,561
Asia-Pacific and Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									$ 64,816	$ 25,184	$ 19,652