Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Supplemental Disclosure of Cash Flow Information:
Interest paid	$ 13,062	$ 13,238
Income taxes paid	88	99
Investing Activities:
Accrued capital expenditures	5,688	1,464
Financing Activities:
Dividend distributions declared, but not paid	$ 38,784	$ 36,309