Stock-based Compensation Plans and Awards - Fair Value Weighted Average Assumptions Stock Options (Details) - Stock options	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Weighted-average assumptions used to estimate the fair values of the stock options
Expected life (in years)	5 years 11 months 9 days	5 years 10 months 21 days	5 years 6 months
Risk-free interest rate	1.69%	1.82%	0.83%
Expected volatility range	53.40%	54.10%	51.00%