Condensed Consolidating Financial Information (Condensed Consolidating Statements of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Net cash provided by (used in) operating activities	$ 1,377,518	$ 1,192,477
Capital investments	(1,727,543)	(1,623,751)
Proceeds from sale of property and equipment	3,081	(201,161)
Transfers to restricted cash		(167,774)
Transfers from restricted cash	8,542	40,700
Other	4,700	5,239
Net cash used in investing activities	(1,711,220)	(1,544,425)
Payments on current portion of long-term debt	(600)	(600)
Payments on revolving long-term debt	(2,134,550)	(1,774,000)
Borrowing under revolving long-term debt	2,377,950	1,129,000
Proceeds from issuance of long-term debt		998,780
Other items	55,857	1,711
Net cash provided by (used in) financing activities	298,657	354,891
Effect of exchange rate changes on cash	412	(10)
Increase (decrease) in cash and cash equivalents	(34,633)	2,933
Cash and cash equivalents at beginning of year	53,583	15,627
Cash and cash equivalents at end of period	18,950	18,560
Parent [Member]
Net cash provided by (used in) operating activities	(32,502)	(55,324)
Capital investments	(29,227)	(38,946)
Proceeds from sale of property and equipment		(144)
Transfers to restricted cash		(167,774)
Transfers from restricted cash	8,542	40,700
Other	(74)	16,575
Net cash used in investing activities	(20,759)	(149,301)
Intercompany activities	(274,931)	(148,027)
Payments on current portion of long-term debt	(600)	(600)
Payments on revolving long-term debt	(2,134,550)	(1,774,000)
Borrowing under revolving long-term debt	2,377,950	1,129,000
Proceeds from issuance of long-term debt		998,780
Other items	55,857	1,722
Net cash provided by (used in) financing activities	23,726	206,875
Increase (decrease) in cash and cash equivalents	(29,535)	2,250
Cash and cash equivalents at beginning of year	47,491	14,711
Cash and cash equivalents at end of period	17,956	16,961
Guarantors [Member]
Net cash provided by (used in) operating activities	1,062,133	915,885
Capital investments	(1,530,760)	(1,452,061)
Proceeds from sale of property and equipment	210	(169,149)
Other	(1,685)	(24,340)
Net cash used in investing activities	(1,532,235)	(1,307,252)
Intercompany activities	464,114	392,732
Net cash provided by (used in) financing activities	464,114	392,732
Increase (decrease) in cash and cash equivalents	(5,988)	1,365
Cash and cash equivalents at beginning of year	5,988
Cash and cash equivalents at end of period		1,365
Non-Guarantors [Member]
Net cash provided by (used in) operating activities	347,887	331,916
Capital investments	(167,556)	(132,744)
Proceeds from sale of property and equipment	2,871	(31,868)
Other	6,459	13,004
Net cash used in investing activities	(158,226)	(87,872)
Intercompany activities	(189,183)	(244,705)
Other items		(11)
Net cash provided by (used in) financing activities	(189,183)	(244,716)
Effect of exchange rate changes on cash	412	(10)
Increase (decrease) in cash and cash equivalents	890	(682)
Cash and cash equivalents at beginning of year	104	916
Cash and cash equivalents at end of period	$ 994	$ 234