Employee Stock and Savings Plans - Schedule of Estimation Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected life	6 years 4 months 24 days	6 years 3 months 18 days	6 years 4 months 24 days
Average risk-free interest rate	1.90%	2.00%	0.90%
Expected volatility (as a percent)	29.20%	29.60%	29.90%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%