Stock-Based Compensation and Other Compensation - Options Rollforward (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding
Outstanding - beginning of year - shares	258,787	475,765	619,601
Exercised - shares	(113,002)	(213,479)	(140,718)
Canceled/Expired - shares	(752)	(3,499)	(3,118)
Outstanding - end of year - shares	145,033	258,787	475,765
Vested and expected to vest - end of year - shares	145,033
Exercisable - end of year - shares	145,033	236,112	421,656
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Outstanding - beginning of year - weighted average exercise price (in dollars per share)	$ 31.10	$ 29.95	$ 30.30
Exercised - weighted average exercise price (in dollars per share)	28.34	28.57	31.41
Canceled/Expired - weighted average exercise price (in dollars per share)	28.42	28.71	32.99
Outstanding - end of year - weighted average exercise price (in dollars per share)	33.27	31.10	29.95
Vested and expected to vest - end of year - weighted average exercise price	33.27
Exercisable - end of year - weighted average exercise price	$ 33.27	$ 30.99	$ 29.75
Outstanding - end of year - weighted average contractual term (in Years)	3 months 18 days	1 year 22 days	1 year 9 months
Vested and expected to vest - end of year - weighted average contractual term (in Years)	3 months 18 days
Exercisable - end of year - weighted average contractual term (in Years)	3 months 18 days
Outstanding - end of year - aggregate intrinsic value	$ 3,745,163
Vested and expected to vest - end of year - aggregate intrinsic value	3,745,163
Exercisable - end of year - aggregate intrinsic value	$ 3,745,163