Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment information
Net revenues	$ 743,811	$ 707,044	$ 712,551	$ 736,059	$ 676,450	$ 710,905	$ 687,879	$ 667,023	$ 2,899,465	$ 2,742,257	$ 2,459,111
Income (loss) from operations	73,293	98,666	128,015	142,615	105,919	130,335	140,592	122,735	442,589	499,581	153,226
Depreciation and amortization									245,348	211,476	212,387
(Loss) gain from unconsolidated affiliates									3,804	7,364	(25,974)
Impairment losses											224,709
Capital expenditures									472,985	293,081	362,955
Total assets	5,644,057				4,606,346				5,644,057	4,606,346
Investment in and advances to unconsolidated affiliates	204,506				174,116				204,506	174,116
Goodwill and other intangible assets, net	2,087,166				1,601,952				2,087,166	1,601,952
Midwest
Segment information
Net revenues									949,464	826,436	825,847
Income (loss) from operations									206,462	211,356	(39,514)
Depreciation and amortization									92,689	62,844	64,402
Impairment losses											220,236
Capital expenditures									388,639	206,081	198,282
Total assets	2,318,283				1,897,164				2,318,283	1,897,164
Goodwill and other intangible assets, net	1,025,505				925,822				1,025,505	925,822
East/West
Segment information
Net revenues									1,345,621	1,290,732	997,262
Income (loss) from operations									291,627	263,423	181,175
Depreciation and amortization									88,688	85,723	79,244
Capital expenditures									43,234	51,701	118,398
Total assets	1,198,391				1,265,438				1,198,391	1,265,438
Investment in and advances to unconsolidated affiliates	87				110				87	110
Goodwill and other intangible assets, net	226,047				226,234				226,047	226,234
Southern Plains
Segment information
Net revenues									571,246	590,709	602,257
Income (loss) from operations									132,153	137,580	125,318
Depreciation and amortization									49,408	53,764	59,777
(Loss) gain from unconsolidated affiliates									5,210	(4,834)	(2,242)
Capital expenditures									35,534	25,488	41,215
Total assets	1,680,773				1,034,506				1,680,773	1,034,506
Investment in and advances to unconsolidated affiliates	138,514				107,204				138,514	107,204
Goodwill and other intangible assets, net	779,787				394,018				779,787	394,018
Other
Segment information
Net revenues									33,134	34,380	33,745
Income (loss) from operations									(187,653)	(112,778)	(113,753)
Depreciation and amortization									14,563	9,145	8,964
(Loss) gain from unconsolidated affiliates									(1,406)	12,198	(23,732)
Impairment losses											4,473
Capital expenditures									5,578	9,811	5,060
Total assets	446,610				409,238				446,610	409,238
Investment in and advances to unconsolidated affiliates	65,905				66,802				65,905	66,802
Goodwill and other intangible assets, net	55,827				55,878				55,827	55,878
Maryland RE & R LLC
Segment information
(Loss) gain from unconsolidated affiliates											$ (14,400)