Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash Flows From Operating Activities:
Net income	$ 75,365	$ 64,889
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	128,733	124,154
Amortization of debt issuance costs and discounts	7,068	8,508
Loss on sale or disposal of assets	1,694	8,129
Loss on early extinguishment of debt and write-off of discounts and deferred financing costs	461	29,858
Deferred income tax provision	45,356	32,375
Equity-based compensation	1,905	4,704
Changes in assets and liabilities:
Accounts receivable	(3,091)	(13,432)
Inventories	(557)	(1,299)
Prepaid expenses and other current assets	1,890	(67)
Accounts payable	(3,746)	(4,029)
Accrued salaries, wages and benefits	(11,595)	(11,788)
Deferred revenue	9,191	16,259
Other accrued expenses	14,162	15,168
Other assets and liabilities	3,103	(445)
Net cash provided by operating activities	269,939	272,984
Cash Flows From Investing Activities:
Capital expenditures	(122,809)	(125,852)
Change in restricted cash	(373)	49
Acquisition of intangible assets	(1,900)
Net cash used in investing activities	(125,082)	(125,803)
Cash Flows From Financing Activities:
Repayment of long-term debt	(42,025)	(185,742)
Repayment of note payable		(3,000)
Proceeds from draw on revolving credit facility	40,000	35,000
Repayment of revolving credit facility	(40,000)	(35,000)
Purchase of treasury stock	(50,708)
Dividends paid to stockholders	(53,639)	(18,124)
Payment of tax withholdings on equity-based compensation through shares withheld	(134)
Redemption premium payment		(15,400)
Proceeds from the issuance of debt		1,455
Proceeds from issuance of common stock, net of underwriter commissions		253,800
Debt issuance costs		(10,635)
Offering costs		(4,694)
Net cash (used in) provided by financing activities	(146,506)	17,660
Change in Cash and Cash Equivalents	(1,649)	164,841
Cash and Cash Equivalents-Beginning of period	116,841	45,675
Cash and Cash Equivalents-End of period	115,192	210,516
Supplemental Disclosures of Noncash Investing and Financing Activities
Capital expenditures in accounts payable	13,616	24,449
Dividends declared, but unpaid	$ 18,647	$ 18,223