Information Concerning Guarantor and Non-Guarantor Subsidiaries - Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 3,872	$ 29,831
Purchases of property and equipment	(18,655)	(17,484)
Proceeds from sale of Peterson LOI	10,000
(Increase) decrease in restricted cash and cash equivalents	(3,594)	9,509
Other investing activities	(2,453)
Net cash provided by (used in) investing activities	(14,702)	(7,975)
Net borrowings under credit facility	171,000	(3,500)
Repayments under term loan B	(1,000)
Repurchase of common stock warrants	(154,681)
Payment of dividend	(28,756)	(25,459)
Proceeds from exercise of stock option and purchase plans	1,015	1,078
Other financing activities, net	(157)	(137)
Net cash provided by (used in) financing activities	(12,579)	(28,018)
Net change in cash and cash equivalents	(23,409)	(6,162)
Cash and cash equivalents - unrestricted, beginning of period	76,408	61,579
Cash and cash equivalents - unrestricted, end of period	52,999	55,417
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	172,169	24,395
Purchases of property and equipment	(22)	(24)
Proceeds from sale of Peterson LOI	10,000
Net cash provided by (used in) investing activities	9,978	(24)
Repurchase of common stock warrants	(154,681)
Payment of dividend	(28,756)	(25,459)
Proceeds from exercise of stock option and purchase plans	1,015	1,078
Other financing activities, net		10
Net cash provided by (used in) financing activities	(182,422)	(24,371)
Net change in cash and cash equivalents	(275)
Cash and cash equivalents - unrestricted, beginning of period	392
Cash and cash equivalents - unrestricted, end of period	117
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(170,289)	8,930
Net borrowings under credit facility	171,000	(3,500)
Repayments under term loan B	(1,000)
Net cash provided by (used in) financing activities	170,000	(3,500)
Net change in cash and cash equivalents	(289)	5,430
Cash and cash equivalents - unrestricted, beginning of period	1,001	714
Cash and cash equivalents - unrestricted, end of period	712	6,144
Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	2	3
Purchases of property and equipment	(2)	(3)
Net cash provided by (used in) investing activities	(2)	(3)
Cash and cash equivalents - unrestricted, beginning of period	36
Cash and cash equivalents - unrestricted, end of period	36
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1,990	(3,497)
Purchases of property and equipment	(18,631)	(17,457)
(Increase) decrease in restricted cash and cash equivalents	(3,594)	9,509
Other investing activities	(2,453)
Net cash provided by (used in) investing activities	(24,678)	(7,948)
Other financing activities, net	(157)	(147)
Net cash provided by (used in) financing activities	(157)	(147)
Net change in cash and cash equivalents	(22,845)	(11,592)
Cash and cash equivalents - unrestricted, beginning of period	74,979	60,865
Cash and cash equivalents - unrestricted, end of period	$ 52,134	$ 49,273