Segment Information (Schedule Of Operating Segment Results) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues	$ 1,039,651	$ 872,938
Income (loss) from operations	54,081	102,238
Total assets	10,165,118		10,213,959
Depreciation, depletion and amortization	139,966	83,537
Amortization of acquired sales contacts, net	(14,017)	5,944
Capital expenditures	93,271	38,711
PRB [Member]
Segment Reporting Information [Line Items]
Revenues	401,177	393,113
Income (loss) from operations	32,543	46,874
Depreciation, depletion and amortization	41,223	41,691
Amortization of acquired sales contacts, net	(816)	5,944
Capital expenditures	3,986	2,838
APP [Member]
Segment Reporting Information [Line Items]
Revenues	469,058	155,439
Income (loss) from operations	15,835	26,892
Depreciation, depletion and amortization	76,017	20,529
Amortization of acquired sales contacts, net	(13,088)
Capital expenditures	66,303	11,777
WBIT [Member]
Segment Reporting Information [Line Items]
Revenues	144,559	324,386
Income (loss) from operations	31,241	54,394
Depreciation, depletion and amortization	18,600	21,016
Capital expenditures	15,137	17,302
Other [Member]
Segment Reporting Information [Line Items]
Revenues	24,857
Income (loss) from operations	(3,750)
Depreciation, depletion and amortization	3,687
Amortization of acquired sales contacts, net	(113)
Capital expenditures	5,644
Corporate, Other and Eliminations [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(21,788)	(25,922)
Depreciation, depletion and amortization	439	301
Capital expenditures	$ 2,201	$ 6,794