Debt Senior Notes (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2012
Debt Instrument [Line Items]
Proceeds from senior notes	$ 0	$ 0	$ 294,750,000
Loss on early extinguishment of debt	(7,677,000)	0	(2,979,000)
Credit agreement restrictions before 2015	206,000,000
Credit agreement restrictions 2015 to 2018	171,000,000
8.25% Interest Rate [Member]
Debt Instrument [Line Items]
Principal				150,000,000
Stated interest rate, senior notes				8.25%
Senior Notes Aggregate Redemption Amount				156,200,000
Loss on early extinguishment of debt				7,700,000
Debt Instrument, Unamortized Premium				6,200,000
Amortization of Financing Costs				1,500,000
6.5% Interest Rate [Member]
Debt Instrument [Line Items]
Principal					300,000,000
Proceeds from senior notes					294,800,000
Stated interest rate, senior notes	6.50%				6.50%
6.25% Interest Rate [Member]
Debt Instrument [Line Items]
Repayment of senior notes					185,000,000
Stated interest rate, senior notes					6.25%
Promissory Notes [Member]
Debt Instrument [Line Items]
Repayment of notes					$ (72,900,000)