Commitments and Contingencies - Amounts of Recorded Liability Related to Claims and Contingencies (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Other current liabilities	$ 42,054		$ 14,976	$ 14,494
Other liabilities	588		598	0
Total	$ 42,642	$ 13,995	$ 15,574	$ 14,494	$ 126,074	$ 125,880