Information Concerning Guarantor and Non-Guarantor Subsidiaries - Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities	$ 157,415	$ 64,206
Net cash provided by (used in) discontinued operating activities	(201)	94
Net cash provided by (used in) operating activities	157,214	64,300
Purchases of property and equipment	(50,728)	(23,584)
(Increase) decrease in restricted cash and cash equivalents	5,936	(12,347)
Other investing activities	8,011	1,967
Net cash provided by (used in) investing activities - continuing operations	(36,781)	(33,964)
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities	(36,781)	(33,964)
Net borrowings (repayments) under credit facility	416,500	(12,000)
Issuance of senior notes		350,000
Early redemption of senior notes		(152,180)
Repurchase and conversion of convertible notes	(126,542)	(99,222)
Repurchase of common stock warrants	(108,331)
Deferred financing costs paid	(8,428)	(15,516)
Repurchase of Company stock for retirement		(100,028)
Payment of dividend	(81,352)	(51,162)
Proceeds from exercise of stock option and purchase plans	6,119	5,206
Other financing activities, net	(445)	(514)
Net cash provided by (used in) financing activities - continuing operations	97,521	(75,416)
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities	97,521	(75,416)
Net change in cash and cash equivalents	217,954	(45,080)
Cash and cash equivalents - unrestricted, beginning of period	61,579	97,170
Cash and cash equivalents - unrestricted, end of period	279,533	52,090
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities
Net cash provided by (used in) discontinued operating activities
Net cash provided by (used in) operating activities
Purchases of property and equipment
(Increase) decrease in restricted cash and cash equivalents
Other investing activities
Net cash provided by (used in) investing activities - continuing operations
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities
Net borrowings (repayments) under credit facility
Issuance of senior notes
Early redemption of senior notes
Repurchase and conversion of convertible notes
Repurchase of common stock warrants
Deferred financing costs paid
Repurchase of Company stock for retirement
Payment of dividend
Proceeds from exercise of stock option and purchase plans
Other financing activities, net
Net cash provided by (used in) financing activities - continuing operations
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities
Net change in cash and cash equivalents
Cash and cash equivalents - unrestricted, beginning of period
Cash and cash equivalents - unrestricted, end of period
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities	316,879	397,379
Net cash provided by (used in) discontinued operating activities
Net cash provided by (used in) operating activities	316,879	397,379
Purchases of property and equipment	(6,650)
(Increase) decrease in restricted cash and cash equivalents
Other investing activities
Net cash provided by (used in) investing activities - continuing operations	(6,650)
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities	(6,650)
Net borrowings (repayments) under credit facility
Issuance of senior notes
Early redemption of senior notes		(152,180)
Repurchase and conversion of convertible notes	(126,542)	(99,222)
Repurchase of common stock warrants	(108,331)
Deferred financing costs paid
Repurchase of Company stock for retirement		(100,028)
Payment of dividend	(81,352)	(51,162)
Proceeds from exercise of stock option and purchase plans	6,119	5,206
Other financing activities, net		7
Net cash provided by (used in) financing activities - continuing operations	(310,106)	(397,379)
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities	(310,106)	(397,379)
Net change in cash and cash equivalents	123
Cash and cash equivalents - unrestricted, beginning of period
Cash and cash equivalents - unrestricted, end of period	123
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities	(168,110)	(322,427)
Net cash provided by (used in) discontinued operating activities
Net cash provided by (used in) operating activities	(168,110)	(322,427)
Purchases of property and equipment	(2,893)
(Increase) decrease in restricted cash and cash equivalents
Other investing activities
Net cash provided by (used in) investing activities - continuing operations	(2,893)
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities	(2,893)
Net borrowings (repayments) under credit facility	416,500	(12,000)
Issuance of senior notes		350,000
Early redemption of senior notes
Repurchase and conversion of convertible notes
Repurchase of common stock warrants
Deferred financing costs paid	(8,428)	(15,516)
Repurchase of Company stock for retirement
Payment of dividend
Proceeds from exercise of stock option and purchase plans
Other financing activities, net
Net cash provided by (used in) financing activities - continuing operations	408,072	322,484
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities	408,072	322,484
Net change in cash and cash equivalents	237,069	57
Cash and cash equivalents - unrestricted, beginning of period	714
Cash and cash equivalents - unrestricted, end of period	237,783	57
Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities	51	37
Net cash provided by (used in) discontinued operating activities
Net cash provided by (used in) operating activities	51	37
Purchases of property and equipment	(10)	558
(Increase) decrease in restricted cash and cash equivalents
Other investing activities
Net cash provided by (used in) investing activities - continuing operations	(10)	558
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities	(10)	558
Net borrowings (repayments) under credit facility
Issuance of senior notes
Early redemption of senior notes
Repurchase and conversion of convertible notes
Repurchase of common stock warrants
Deferred financing costs paid
Repurchase of Company stock for retirement
Payment of dividend
Proceeds from exercise of stock option and purchase plans
Other financing activities, net
Net cash provided by (used in) financing activities - continuing operations
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities
Net change in cash and cash equivalents	41	595
Cash and cash equivalents - unrestricted, beginning of period		(595)
Cash and cash equivalents - unrestricted, end of period	41
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) continuing operating activities	8,595	(10,783)
Net cash provided by (used in) discontinued operating activities	(201)	94
Net cash provided by (used in) operating activities	8,394	(10,689)
Purchases of property and equipment	(41,175)	(24,142)
(Increase) decrease in restricted cash and cash equivalents	5,936	(12,347)
Other investing activities	8,011	1,967
Net cash provided by (used in) investing activities - continuing operations	(27,228)	(34,522)
Net cash used in investing activities - discontinued operations
Net cash provided by (used in) investing activities	(27,228)	(34,522)
Net borrowings (repayments) under credit facility
Issuance of senior notes
Early redemption of senior notes
Repurchase and conversion of convertible notes
Repurchase of common stock warrants
Deferred financing costs paid
Repurchase of Company stock for retirement
Payment of dividend
Proceeds from exercise of stock option and purchase plans
Other financing activities, net	(445)	(521)
Net cash provided by (used in) financing activities - continuing operations	(445)	(521)
Net cash used in financing activities - discontinued operations
Net cash provided by (used in) financing activities	(445)	(521)
Net change in cash and cash equivalents	(19,279)	(45,732)
Cash and cash equivalents - unrestricted, beginning of period	60,865	97,765
Cash and cash equivalents - unrestricted, end of period	$ 41,586	$ 52,033