Long-Term Debt - Schedule of Impact of Corrections on Affected Financial Statements (Consolidated Balance Sheet Line Items) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Balance Sheet Data:
Other assets	$ 31,316	$ 35,890
Total assets	2,442,474	2,577,410
Long-term debt	1,589,403	1,632,531
Deferred tax liabilities, net	31,760	25,670
Retained earnings	33,516	1,886
Total stockholders' equity	579,535	648,027	442,301	868,143
Total liabilities and stockholders' equity	2,442,474	2,577,410
As Previously Reported [Member]
Selected Balance Sheet Data:
Other assets		40,753
Total assets		2,582,273
Long-term debt		1,627,183
Deferred tax liabilities, net		29,776
Retained earnings		7,991
Total stockholders' equity		654,132
Total liabilities and stockholders' equity		2,582,273
Adjustments [Member]
Selected Balance Sheet Data:
Other assets		(4,863)
Total assets		(4,863)
Long-term debt		5,348
Deferred tax liabilities, net		(4,106)
Retained earnings		(6,105)
Total stockholders' equity		(6,105)
Total liabilities and stockholders' equity		(4,863)
Scenario as Revised [Member]
Selected Balance Sheet Data:
Other assets		35,890
Total assets		2,577,410
Long-term debt		1,632,531
Deferred tax liabilities, net		25,670
Retained earnings		1,886
Total stockholders' equity		648,027
Total liabilities and stockholders' equity		$ 2,577,410