Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Disclosure of Cash Flow Information
Cash paid for interest, net of amounts capitalized	$ (296,386)	$ (235,793)	$ (274,850)
Cash (paid) received for income taxes	(88)	1,928	(4,610)
Supplemental Disclosure of Noncash Investing and Financing Activities
Deposit on pending sale	0	0	(255,000)
Change in accrued capital expenditures	177,586	(55,557)	72,848
Equity issued for debt	(63,299)	0	0
Preferred stock dividends paid in common stock	(16,188)	0	0
Long-term debt issued, including derivative and net of discount, for asset acquisition and termination of gathering agreement	$ (50,310)	$ 0	$ 0