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	$ 221,854	$ 195,022	$ 300,835
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	151,514	113,925	113,491
Asset impairments	955	30,082	9,150
Amortization of debt issuance costs and other non-cash interest	2,973	3,102	3,509
Expenses associated with debt refinancing transactions	701		36,528
Deferred income taxes	5,706	(3,211)	(151,037)
Other expenses and non-cash items	3,732	4,594	2,623
Non-cash revenue and other income	(2,639)	(3,880)	(294)
Income tax benefit of equity compensation	(525)	(665)	(351)
Non-cash equity compensation	15,394	13,975	12,965
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets	1,266	(12,549)	16,683
Accounts payable, accrued expenses and other liabilities	(2,210)	82,396	23,910
Income taxes payable	1,077	790	1,492
Net cash provided by operating activities	399,798	423,581	369,504
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions	(164,880)	(85,791)	(27,955)
Expenditures for other capital improvements	(59,414)	(49,315)	(48,570)
Capitalized lease payments	(34,470)	(70,793)
Acquisition of businesses, net of cash acquired	(158,366)		(36,252)
Cash paid for leasehold incentive			(12,765)
Decrease in restricted cash	1,350	2,983	452
Proceeds from sale of assets	563	5,136	998
Decrease (increase) in other assets	3,686	(1,101)	(3,260)
Payments received on direct financing lease and notes receivable	2,250	1,994	1,840
Net cash used in investing activities	(409,281)	(196,887)	(125,512)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt	807,000	250,000	1,283,000
Principal repayments of debt	(543,000)	(255,000)	(1,198,000)
Payment of debt issuance and other refinancing and related costs	(5,727)		(37,349)
Payment of lease obligations	(6,468)
Proceeds from exercise of stock options	7,700	12,450	30,171
Purchase and retirement of common stock	(9,454)	(4,036)	(6,693)
Income tax benefit of equity compensation	525	665	351
Decrease (increase) in restricted cash for dividends	500	(251)	(1,016)
Dividends paid	(250,695)	(234,048)	(299,434)
Net cash provided by (used in) financing activities	381	(230,220)	(228,970)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(9,102)	(3,526)	15,022
CASH AND CASH EQUIVALENTS, beginning of year	74,393	77,919	62,897
CASH AND CASH EQUIVALENTS, end of year	65,291	74,393	77,919
Cash paid during the period for:
Interest (net of amounts capitalized of $5,478, $2,525, and $836 in 2015, 2014, and 2013, respectively)	36,992	39,928	40,776
Income taxes	$ 9,966	$ 19,717	$ 7,422