Supplemental Balance Sheet, Income Statement and Cash Flow Information (Details 6) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental cash flow information
Cash paid for income taxes	$ (66,910)	$ (166,660)	$ (100,749)
Cash paid for interest, net of capitalized interest	168,979	164,928	239,637
Net change in accounts payable related to capital expenditures	(59,565)	28,011	116,971
Acquisitions of businesses:
Fair value of assets acquired	327,857	59,195	140,740
Goodwill	86,502	18,818	51,318
Liabilities assumed	(306,084)	(2,796)	(8,232)
Gain on acquisition	(2,308)
Future consideration (fair value)		(24,735)	(64,174)
Payments on future consideration	22,278	22,278
Cash paid for acquisitions of businesses	128,245	72,760	119,652
Cash acquired in acquisitions of businesses	(48,058)	(226)	(2,681)
Cash paid for acquisition of businesses, net	$ (80,187)	$ (72,534)	$ (116,971)