Stock-Based Compensation - Significant Option Groups Outstanding and Related Weighted Average Exercise Price and Life Information (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options Outstanding
Number outstanding (in shares)	745	597	520	652
Weighted-average remaining contractual term (in years)	3 years 11 months 19 days	4 years 29 days	4 years 3 months
Weighted average exercise price (in dollars per share)	$ 41.73	$ 44.27	$ 42.56	$ 39.27
Options Exercisable
Number exercisable (in shares)	517	430	381
Weighted-average exercise price (in dollars per share)	$ 44.95	$ 42.30	$ 36.39
$19.25 to $27.07
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of exercise prices, lower range limit (in dollars per share)	19.25
Range of exercise prices, upper range limit (in dollars per share)	$ 27.07
Options Outstanding
Number outstanding (in shares)	263
Weighted-average remaining contractual term (in years)	4 years 8 months 19 days
Weighted average exercise price (in dollars per share)	$ 23.83
Options Exercisable
Number exercisable (in shares)	112
Weighted-average exercise price (in dollars per share)	$ 19.49
$35.28 to $44.95
Share-based Payment Arrangement, Option, 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)	$ 44.95
Options Outstanding
Number outstanding (in shares)	200
Weighted-average remaining contractual term (in years)	3 years 6 months
Weighted average exercise price (in dollars per share)	$ 41.04
Options Exercisable
Number exercisable (in shares)	150
Weighted-average exercise price (in dollars per share)	$ 39.75
$51.38 to $65.54
Share-based Payment Arrangement, Option, 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
Number outstanding (in shares)	282
Weighted-average remaining contractual term (in years)	3 years 7 months 13 days
Weighted average exercise price (in dollars per share)	$ 58.85
Options Exercisable
Number exercisable (in shares)	255
Weighted-average exercise price (in dollars per share)	$ 59.21