Stock-Based Compensation Stock Option Black Scholes Option Pricing Model Assumptions (Details) (Employee Stock Option [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	39.30%	38.10%	42.10%
Risk-free interest rate	1.70%	1.00%	0.80%
Expected term (years)	5 years 6 months 2 days	5 years 6 months	5 years 1 month