Debt (5.875% Senior Notes) (Details) (USD $)				12 Months Ended						12 Months Ended								12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2010	Dec. 31, 2013 5.875% Senior Notes Redemption, Period 2017	Dec. 31, 2013 5.875% Senior Notes Redemption, Period 2018	Dec. 31, 2013 5.875% Senior Notes Redemption, Period 2019	Dec. 31, 2013 5.875% Senior Notes Redemption, Period 2020 and Thereafter	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member]	Mar. 19, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member]	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Redemption, Period 2017	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Redemption, Period 2018	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Redemption, Period 2019	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Redemption, Period 2020 and Thereafter	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Maximum	Dec. 31, 2013 Senior Notes Five Point One Two Five Percent Senior Notes [Member] Minimum	Dec. 31, 2013 Senior Notes 5.875% Senior Notes	Oct. 03, 2013 Senior Notes 5.875% Senior Notes	Dec. 31, 2013 Senior Notes 5.875% Senior Notes Maximum	Dec. 31, 2013 Senior Notes 5.875% Senior Notes Minimum
Debt Instrument [Line Items]
Debt instrument, face amount									$ 300,000,000								$ 250,000,000
Stated interest rate			8.47%						5.125%								5.875%
Debt Instrument, Notice Period Prior to Redemption														0 years 0 months 60 days	0 years 0 months 30 days			0 years 0 months 60 days	0 years 0 months 30 days
Debt Instrument, Redemption Period, Change in Control, Percentage of Principal Amount Redeemable								101.00%								101.00%
Redemption price percentage				104.406%	102.938%	101.469%	100.00%	105.125%		102.563%	101.708%	100.854%	100.00%			100.00%
Redemption period, principal amount redeemable								35.00%								35.00%
Debt Instrument, Redemption Price Including Accrued Interest And Liquidated Damages, Percentage																105.875%
Debt Covenant, Asset Proceeds, Excess Proceeds								25,000,000								25,000,000
Debt Covenant, Indenture Agreement, Period After Notice								60 days								60 days
Capitalized loan costs	$ 33,100,000	$ 23,400,000						$ 6,800,000								$ 5,900,000