Stock-based Compensation - Schedule of Employee Stock Purchase Plan Assumptions (Details) - Employee stock purchase plan - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Share-based Compensation, Employee Stock Purchase Plan Assumptions [Line Items]
Expected life (years)	6 months	6 months	6 months
Risk-free interest rate	0.10%	0.03%	0.10%
Volatility	30.90%	24.70%	30.30%
Dividend yield	1.20%	1.00%	1.40%
Fair value per share of the 15% cash discount	$ 8.79	$ 9.72	$ 6.45
Fair value per share of the look-back provision	4.97	4.39	3.58
Total weighted average fair value per share at grant date	$ 13.76	$ 14.11	$ 10.03