Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash paid during the period for:
Interest	$ 96,958	$ 98,754	$ 114,301
Income taxes	52,040	16,610	17,585
Non-cash investing and financing activities:
Issuance of stock dividend	584	520	450
Acquisitions	0	0	84,859
Non-controlling interest	0	2,733	87,657
Debt retired in conversion to stock	25,000	132,530	43,222
Embedded derivative, net retired in conversion to stock	$ 889	$ 6,680	$ 17,377