Long-term Debt (8.50% Senior Notes) (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2009
Debt Instrument [Line Items]
Interest paid		$ 111,761,000	$ 41,085,000	$ 19,114,000
Loss on extinguishment of debt		$ 0	$ 0	$ 25,129,000
Senior Notes [Member] | 8.50% Senior Notes [Member]
Debt Instrument [Line Items]
Face amount	$ 200,000,000.0				$ 200,000,000.0
Interest rate	8.50%				8.50%
Make-whole premium	$ 19,400,000
Interest paid	5,100,000
Loss on extinguishment of debt	25,100,000
Write off of unamortized deferred financing costs	$ 4,200,000