Stock-Based Compensation - Exercise Price Range (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding (in shares)	652	648	650	924
Weighted-Average Remaining Years of Contractual Life	4 years 9 months 10 days	4 years 10 months 5 days	5 years 7 months 2 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 39.27	$ 30.50	$ 25.56	$ 22.04
Exercisable at the end of the year (in shares)	363	493	421
Exercisable at the end of the year (in dollars per share)	$ 30.21	$ 25.03	$ 23.84
$18.25 to $21.95
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range limit (in dollars per share)	18.25
Range of exercise prices, upper range limit (in dollars per share)	$ 21.95
Options outstanding (in shares)	182
Weighted-Average Remaining Years of Contractual Life	4 years 5 months 8 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.15
Exercisable at the end of the year (in shares)	180
Exercisable at the end of the year (in dollars per share)	$ 20.13
26.48 to 28.08
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range limit (in dollars per share)	26.48
Range of exercise prices, upper range limit (in dollars per share)	$ 28.08
Options outstanding (in shares)	56
Weighted-Average Remaining Years of Contractual Life	9 months 18 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 27.45
Exercisable at the end of the year (in shares)	56
Exercisable at the end of the year (in dollars per share)	$ 27.45
35.28 to 48.61
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range limit (in dollars per share)	35.28
Range of exercise prices, upper range limit (in dollars per share)	$ 48.61
Options outstanding (in shares)	243
Weighted-Average Remaining Years of Contractual Life	5 years 4 months 6 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 43.49
Exercisable at the end of the year (in shares)	84
Exercisable at the end of the year (in dollars per share)	$ 35.28
51.38 to 65.54
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range limit (in dollars per share)	51.38
Range of exercise prices, upper range limit (in dollars per share)	$ 65.54
Options outstanding (in shares)	171
Weighted-Average Remaining Years of Contractual Life	5 years 7 months 13 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 57.49
Exercisable at the end of the year (in shares)	43
Exercisable at the end of the year (in dollars per share)	$ 65.22