Commitments and Contingencies - Components of Recorded Liability Related to Claims and Contingencies (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Schedule of Claims and Contingencies [Line Items]
Total	$ 14,494	$ 126,074	$ 125,880	$ 44,860	$ 38,725	$ 126,978
Other current liabilities	14,494		25,893	44,472
Other liabilities	0		99,987	388
Total	14,494	126,074	125,880	44,860	38,725	126,978
2009 RSA [Member]
Schedule of Claims and Contingencies [Line Items]
Total	0		116,923	36,535
Total	0		116,923	36,535
Other claims and contingencies [Member]
Schedule of Claims and Contingencies [Line Items]
Total	14,494		8,957	8,325
Total	$ 14,494		$ 8,957	$ 8,325