Stock-Based Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Y
SAR's 2010 [Member]
Assumptions to estimate fair value of stock options and SAR's
Weighted average fair value of stock options granted and SAR's outstanding	$ 16.63
Expected volatility	82.00%
Expected life	4.2
Risk-free interest rate	0.64%
Expected dividend yield	0.00%
SAR's 2009 [Member]
Assumptions to estimate fair value of stock options and SAR's
Weighted average fair value of stock options granted and SAR's outstanding	$ 16.67
Expected volatility	71.10%
Expected life	3.1
Risk-free interest rate	0.38%
Date of Grant [Member] | Stock Options 2011 [Member]
Assumptions to estimate fair value of stock options and SAR's
Weighted average fair value of stock options granted and SAR's outstanding	$ 17.85
Expected volatility	72.56%
Expected life	6.0
Risk-free interest rate	2.30%
Expected dividend yield	0.00%
Date of Grant [Member] | Stock Options 2010 [Member]
Assumptions to estimate fair value of stock options and SAR's
Weighted average fair value of stock options granted and SAR's outstanding	$ 9.96
Expected volatility	73.00%
Expected life	6.0
Risk-free interest rate	2.00%
Expected dividend yield	0.00%
Date of Grant [Member] | SAR's 2010 [Member]
Assumptions to estimate fair value of stock options and SAR's
Weighted average fair value of stock options granted and SAR's outstanding	$ 10.19
Expected volatility	73.70%
Expected life	6.0
Risk-free interest rate	2.70%