Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income (loss)	$ 40,832	$ 24,652
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	137,792	109,112
Accretion on asset retirement obligation	82	99
Change in allowance for doubtful accounts	740	(1,069)
Amortization of deferred financing costs	2,094	1,653
Amortization and retirement of discount or premium on notes	(155)	6,436
Non-cash compensation	9,038	5,920
Loss on early extinguishment of debt (non-cash)		3,940
Premium on retirement of 11.625% senior secured notes		36,179
(Gain) loss on disposal of assets	3,123	(698)
Deferred income taxes	23,587	9,574
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	18,859	(75,602)
Inventories	(6,112)	(7,673)
Prepaid expenses and other current assets	(1,993)	1,465
Other assets	1,370	(3,220)
Accounts payable	361	10,712
Excess tax expense (benefit) from exercise of employee stock options / vesting of restricted stock		(5,034)
Income tax payable	(1,864)	84,209
Other liabilities	1,970	(6,958)
Accrued expenses	3,847	8,811
Net cash provided by operating activities	233,571	202,508
Cash flows from investing activities:
Purchase of property and equipment	(126,694)	(167,114)
Proceeds from sale of assets	5,590	19,194
Payments for other long-term assets	(551)	(462)
Payments for businesses, net of cash acquired	(43,117)	(215,948)
Net cash used in investing activities	(164,772)	(364,330)
Cash flows from financing activities:
Proceeds from debt		498,850
Payments of debt	(30,598)	(269,192)
Premium on retirement of 11.625% senior secured notes		(36,179)
Purchase of treasury stock	(14,925)	(1,872)
Excess tax (expense) benefit from exercise of employee stock options / vesting of restricted stock		5,034
Tax withholding from exercise of stock options	(128)	(3,017)
Exercise of employee stock options	794	7,318
Deferred loan costs and other financing activities	1,162	(15,426)
Net cash provided by (used in) financing activities	(43,695)	185,516
Net increase in cash and equivalents	25,104	23,694
Cash and cash equivalents - beginning of period	78,458	47,918
Cash and cash equivalents - end of period	$ 103,562	$ 71,612