Stock-Based Compensation Stock Option Black Scholes Option Pricing Model Assumptions (Details) (Employee Stock Option [Member])	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Stock Option [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	42.10%	46.50%	48.70%
Risk-free interest rate	0.80%	1.60%	2.30%
Expected life (years)	5 years 1 month	4 years 11 months	4 years 7 months