Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]
Cash paid for interest	$ 93,946	$ 102,880	$ 97,129
Cash paid for income taxes	40,074	127,132	164,158
Details of business acquisitions:
Fair Value of Assets Acquired		29,468	34,964
Fair value of liabilities		(5,125)	(10,942)
Cash paid		24,343	24,022
Less cash acquired		(16)	(225)
Net cash paid for acquisitions		24,327	23,797
Non-cash investing activity:
Capital Expenditures Incurred but Not yet Paid	$ 28,704	$ 49,118	70,463
Non-cash financing activity:
Dividends, Share-based Compensation, Cash			$ 12,759