Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows from Operating Activities:
Net income	$ 411,168	$ 395,727
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation & amortization	205,460	196,255
Stock-based compensation expense	24,693	20,474
Changes in assets & liabilities, net of effects from acquisitions and dispositions:
Accounts receivable	(45,729)	(95,013)
Accrued interest	9,158	(1,520)
Accrued and deferred income taxes	17,997	10,870
Other working capital accounts	123,315	(10,899)
Other assets and deferred charges	(8,149)	4,074
Other	52,050	2,163
Accrued insurance expense, net of commercial premiums paid	44,231	50,511
Payments made in settlement of self-insurance claims	(33,012)	(41,039)
Net cash provided by operating activities	801,182	531,603
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(247,715)	(170,580)
Acquisition of property and businesses	(27,525)	(34,500)
Net cash used in investing activities	(275,240)	(205,080)
Cash Flows from Financing Activities:
Reduction of long-term debt	(843,351)	(255,658)
Additional borrowings and related funds	1,022,239	5,200
Acquisition of noncontrolling interests in majority owned businesses	(418,000)	0
Financing costs	(10,734)	0
Repurchase of common shares	(239,139)	(68,157)
Dividends paid	(19,484)	(19,804)
Issuance of common stock	4,362	4,039
Excess income tax benefits related to stock-based compensation	35,247	28,489
Profit distributions to noncontrolling interests	(59,615)	(23,295)
Proceeds received from sale/leaseback of real property	0	12,765
Net cash used in financing activities	(528,475)	(316,421)
Effect of exchange rate changes on cash and cash equivalents	(2,422)	293
(Decrease) increase in cash and cash equivalents	(4,955)	10,395
Cash and cash equivalents, beginning of period	61,228	32,069
Cash and cash equivalents, end of period	56,273	42,464
Supplemental Disclosures of Cash Flow Information:
Interest paid	53,558	55,718
Income taxes paid, net of refunds	165,947	166,637
Noncash purchases of property and equipment	$ 42,747	$ 34,488