Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net income	$ 49,133	$ 49,919	$ 51,920
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	182,503	176,275	166,086
Amortization of debt issuance costs and discounts	6,409	9,399	10,869
Loss on sale or disposal of assets	6,685	5,792	10,100
Loss on early extinguishment of debt and write-off of discounts and debt issuance costs	20,905	461	29,858
Loss on derivatives	287
Deferred income tax provision	23,246	28,000	24,728
Equity-based compensation	6,527	2,349	6,025
Changes in assets and liabilities:
Accounts receivable	(3,622)	6,256	(3,215)
Inventories	1,234	2,709	(166)
Prepaid expenses and other current assets	835	(1,276)	(5,343)
Accounts payable	2,523	(8,791)	4,293
Accrued salaries, wages and benefits	(6,738)	(4,928)	(9,092)
Deferred revenue	943	(6,089)	94
Other accrued expenses	(2,347)	(763)	(824)
Other assets and liabilities	(2,249)	2,219	1,128
Net cash provided by operating activities	286,274	261,532	286,461
Cash Flows From Investing Activities:
Capital expenditures	(157,302)	(154,641)	(166,258)
Acquisition of intangible assets	(120)	(1,900)
Change in restricted cash	45	(5)	(118)
Net cash used in investing activities	(157,377)	(156,546)	(166,376)
Cash Flows From Financing Activities:
Repayment of long-term debt	(306,150)	(45,537)	(189,255)
Purchase of treasury stock	(50,650)	(60,058)	(44,163)
Proceeds from draw on revolving credit facility	60,000	40,000	35,000
Repayment of revolving credit facility	(45,000)	(40,000)	(35,000)
Dividends paid to stockholders	(72,318)	(72,113)	(36,175)
Proceeds from the issuance of debt	280,000		1,455
Debt issuance costs	(4,571)		(10,635)
Payment of tax withholdings on equity-based compensation through shares withheld	(843)	(213)	(852)
Proceeds from issuance of common stock in initial public offering, net of underwriter commissions			253,800
Repayment of note payable			(3,000)
Redemption premium payment	(14,300)		(15,400)
Offering costs			(4,694)
Net cash used in financing activities	(153,832)	(177,921)	(48,919)
Change in Cash and Cash Equivalents	(24,935)	(72,935)	71,166
Cash and Cash Equivalents—Beginning of period	43,906	116,841	45,675
Cash and Cash Equivalents—End of period	18,971	43,906	116,841
Supplemental Disclosures of Noncash Investing and Financing Activities
Dividends declared, but unpaid	430	172	17,939
Capital expenditures in accounts payable	$ 28,743	25,730	$ 27,160
Treasury stock purchases settled in January 2015		$ 5,650