Stock-Based Compensation Plans (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, beginning balance	64,623	134,389	73,087
Weighted Average Grant Date Fair Value, beginning balance	$ 11.37	$ 15.95	$ 41.50
Granted, Number of Shares	205,463	2,363	98,983
Granted, Weighted Average Exercise Price	$ 27.37	$ 15.30	$ 6.90
Vested, Number of Shares	85,323	(57,926)	(32,084)
Vested, Weighted Average Exercise Price	$ 19.36	$ 21.90	$ 41.65
Cancelled/forfeited, Number of Shares	(11,254)	(14,203)	(5,597)
Cancelled/forfeited, Weighted Average Grant Date Fair Value	$ 26.89	$ 12.43	$ 42.32
Outstanding, Ending Balance	173,509	64,623	134,389
Weighted Average Grant Date Fair Value, Ending Balance	$ 25.38	$ 11.37	$ 15.95
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, beginning balance	126,416	67,485
Weighted Average Grant Date Fair Value, beginning balance	$ 27.32	$ 18.06
Granted, Number of Shares	0	91,378	67,485
Granted, Weighted Average Exercise Price	$ 0	$ 15.40	$ 6.90
Vested, Number of Shares	(79,014)	(22,500)
Vested, Weighted Average Exercise Price	$ 12.60	$ 15.24
Cancelled/forfeited, Number of Shares	(1,884)	(9,947)
Cancelled/forfeited, Weighted Average Grant Date Fair Value	$ 13.93	$ 15.76
Outstanding, Ending Balance	45,518	126,416	67,485
Weighted Average Grant Date Fair Value, Ending Balance	$ 24.14	$ 27.32	$ 18.06
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, beginning balance	100,828	136,298	54,767
Weighted Average Grant Date Fair Value, beginning balance	$ 16.29	$ 16.59	$ 47.40
Granted, Number of Shares	81,489	2,363	98,233
Granted, Weighted Average Exercise Price	$ 42.72	$ 18.65	$ 8.60
Vested, Number of Shares	(56,830)
Vested, Weighted Average Exercise Price	$ 23.24
Cancelled/forfeited, Number of Shares	(19,558)	(37,833)	(16,702)
Cancelled/forfeited, Weighted Average Grant Date Fair Value	$ 48.62	$ 17.53	$ 46.70
Outstanding, Ending Balance	105,929	100,828	136,298
Weighted Average Grant Date Fair Value, Ending Balance	$ 26.92	$ 16.29	$ 16.59
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, beginning balance	145,023	67,485	0
Weighted Average Grant Date Fair Value, beginning balance	$ 35.41	$ 27.53	$ 0
Granted, Number of Shares	0	91,378	67,485
Granted, Weighted Average Exercise Price	$ 0	$ 19.94	$ 8.60
Vested, Number of Shares	(57,948)
Vested, Weighted Average Exercise Price	$ 8.89
Cancelled/forfeited, Number of Shares	(2,536)	(13,840)
Cancelled/forfeited, Weighted Average Grant Date Fair Value	$ 16.32	$ 20.12
Outstanding, Ending Balance	84,539	145,023	67,485
Weighted Average Grant Date Fair Value, Ending Balance	$ 39.78	$ 35.41	$ 27.53