Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 95,522	$ 103,890
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	73,057	84,404
Asset impairments	259
Amortization of debt issuance costs and other non-cash interest	1,566	1,577
Deferred income taxes	2,198	2,050
Non-cash revenue and other income	(10,740)	(2,204)
Income tax benefit of equity compensation		(25)
Non-cash equity compensation	8,145	7,873
Other expenses and non-cash items	1,964	2,192
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets	27,952	22,079
Accounts payable, accrued expenses and other liabilities	(15,907)	(7,754)
Income taxes payable	(1,233)	(756)
Net cash provided by operating activities	182,783	213,326
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions	(13,862)	(18,725)
Expenditures for other capital improvements	(20,929)	(20,695)
Acquisitions, net of cash acquired	(14,077)	(43,618)
Decrease in restricted cash		240
Proceeds from sale of assets	100	8,192
Decrease in other assets	4,893	833
Payments received on direct financing lease and notes receivable	684	1,231
Net cash used in investing activities	(43,191)	(72,542)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt and borrowings from credit facility	120,500	201,000
Scheduled principal repayments	(5,000)	(2,500)
Other principal repayments of debt	(144,500)	(196,000)
Payment of debt issuance and other refinancing and related costs	(65)	(68)
Payment of lease obligations	(1,149)	(6,702)
Contingent consideration for acquisition of businesses		(1,073)
Dividends paid	(101,064)	(128,550)
Income tax benefit of equity compensation		25
Purchase and retirement of common stock	(5,818)	(3,947)
Decrease in restricted cash for dividends		550
Proceeds from exercise of stock options	6,377	2,033
Net cash used in financing activities	(130,719)	(135,232)
NET INCREASE IN CASH AND CASH EQUIVALENTS	8,873	5,552
CASH AND CASH EQUIVALENTS, beginning of period	37,711	65,291
CASH AND CASH EQUIVALENTS, end of period	46,584	70,843
Cash paid during the period for:
Interest (net of amounts capitalized of $0 and $164 in 2017 and 2016, respectively)	28,786	28,655
Income taxes paid (refunded), net	$ 2,295	$ (10,520)