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	$ 241,840	$ 158,405	$ 143,202
Adjustments to reconcile net income to net cash flows from operating activities:
(Income) from discontinued operations, net of income taxes	(50,924)	(23,794)	(20,111)
Depreciation	111,214	107,303	97,108
Amortization	81,050	73,234	63,561
Provision for share based compensation	22,925	15,574	10,383
Deferred income tax (benefit) expense	8,930	(26,632)	(6,827)
Debt amortization	21,945	31,636	24,849
(Gain) loss on disposal of equipment	438	(316)	13
Other	234
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	(9,257)	13,169	(22,308)
Other assets	(7,675)	(52,479)	(22,891)
Accounts payable	21,345	6,771	(36,361)
Accrued wages	3,735	1,859	6,888
Interest payable	(8,083)	57,439	25,992
Income tax payable	(25,085)	5,824	15,446
Accrued expenses and other liabilities	(1,864)	41,498	39,825
Net cash flows from continuing operating activities	410,768	409,491	318,769
Net cash flows from discontinued operating activities	7,222	53,232	65,318
Total net cash flows from operating activities	417,990	462,723	384,087
CASH FLOWS FROM INVESTING ACTIVITIES:
Business acquisitions, net of cash acquired of $204, $0 and $0	(94,376)	(398,060)
Purchase of property and equipment	(136,810)	(130,318)	(114,260)
Other	(1,247)	4,002	(7,622)
Net cash flows from continuing investing activities	(232,433)	(524,376)	(121,882)
Net cash flows from discontinued investing activities	275,815	(20,530)	(13,626)
Total net cash flows from investing activities.	43,382	(544,906)	(135,508)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of notes		1,000,000
Proceeds from term loan facility	250,000	350,000
Payments on notes and term loan facilities		(1,150,000)	(450,000)
Proceeds from initial public offering, net of offering costs			398,066
Proceeds from issuance of long-term revolving credit obligations	139,000	382,765	85,000
Payments on long-term revolving credit obligations	(324,000)	(197,765)	(85,000)
Dividends paid	(75,161)	(75,702)	(56,674)
Debt issuance costs	(4,848)	(27,330)	(30,760)
Principal repayments on long-term obligations	(323,661)	(251,560)	(42,309)
Debt redemption premiums paid on senior and subordinated notes		(61,708)	(16,502)
Repurchases of common stock	(59,957)
Proceeds from stock options exercised and ESPP shares issued including excess tax benefits	10,384	6,273	1,360
Other			(9)
Net cash flows from continuing financing activities	(388,243)	(25,027)	(196,828)
Net cash flows from discontinued financing activities	0	0	0
Total net cash flows from financing activities	(388,243)	(25,027)	(196,828)
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	(5,852)	(7,770)	(821)
NET CHANGE IN CASH AND CASH EQUIVALENTS	67,277	(114,980)	50,930
CASH AND CASH EQUIVALENTS, Beginning of period	115,061	230,041	179,111
CASH AND CASH EQUIVALENTS, End of period	$ 182,338	$ 115,061	$ 230,041