Preferred Shares Preferred Shares (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Mar. 15, 2007
Preferred Shares [Abstract]
Impairment Charges Reduction in Gross Margin	$ 2,000,000	$ 1,000,000	$ 0	$ 0	$ 4,000,000	$ 2,000,000	$ 5,000,000	$ 11,000,000
Impairment Charges Reducing Net Income	1,000,000	(1,000,000)	400,000	100,000	2,800,000	1,100,000	3,400,000	6,900,000
Impairment Charges Reducing EPS	$ 0.05	$ (0.05)	$ 0.02	$ 0.00	$ 0.15	$ 0.06	$ 0.18	$ 0.37
Preferred Stock, Shares Authorized	2,000,000				2,000,000				2,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01				$ 0.01				$ 0.01
Shares, Issued										4,000,000
Preferred Stock, Shares Issued	4,000				4,000				4,000	4,000
Preferred Stock, Value, Issued	100,000,000								100,000,000
Dividends, Preferred Stock									0
Preferred Stock, Dividend Rate, Percentage									9.75%
Restricted Payments Basket	$ 39,400,000								$ 39,400,000