Stock-Based Compensation - Summary of Restricted Stock, Stock Grants, Stock Units and Performance Shares (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restricted Stock Units, Stock Grants, and Stock Units
Stocks granted and the weighted average fair value
Units granted (in shares)	141,811	152,651	179,291
Grant date fair value (in dollars per share)	$ 67.34	$ 64.12	$ 54.89
Number of granted awards to be settled in cash (in shares)	43,952	45,104	49,018
Performance Shares
Stocks granted and the weighted average fair value
Units granted (in shares)	166,666	151,430	166,244
Grant date fair value (in dollars per share)	$ 66.60	$ 64.97	$ 54.86