Stock Based Compensation - Stock Options (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	$ 9.46
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 24.07
Options outstanding, number of shares (in shares) | shares	694
Options outstanding, weighted average remaining contractual life	6 years 3 months 11 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.43
Options exercisable, number of shares (in shares) | shares	694
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.43
Range 01
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	9.46
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 9.46
Options outstanding, number of shares (in shares) | shares	1
Options outstanding, weighted average remaining contractual life	2 years 9 months 18 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 9.46
Options exercisable, number of shares (in shares) | shares	1
Options exercisable, weighted average exercise price (in dollars per share)	$ 9.46
Range 02
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	10.65
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 10.65
Options outstanding, number of shares (in shares) | shares	3
Options outstanding, weighted average remaining contractual life	3 years 9 months 29 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.65
Options exercisable, number of shares (in shares) | shares	3
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.65
Range 03
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	10.76
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 10.76
Options outstanding, number of shares (in shares) | shares	2
Options outstanding, weighted average remaining contractual life	9 months 18 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.76
Options exercisable, number of shares (in shares) | shares	2
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.76
Range 04
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	20.29
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 20.29
Options outstanding, number of shares (in shares) | shares	71
Options outstanding, weighted average remaining contractual life	5 years 9 months
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.29
Options exercisable, number of shares (in shares) | shares	71
Options exercisable, weighted average exercise price (in dollars per share)	$ 20.29
Range 05
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	20.36
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 20.36
Options outstanding, number of shares (in shares) | shares	3
Options outstanding, weighted average remaining contractual life	5 years 7 months 17 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.36
Options exercisable, number of shares (in shares) | shares	3
Options exercisable, weighted average exercise price (in dollars per share)	$ 20.36
Range 06
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	22.20
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 22.20
Options outstanding, number of shares (in shares) | shares	74
Options outstanding, weighted average remaining contractual life	5 years 11 months 23 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.20
Options exercisable, number of shares (in shares) | shares	74
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.20
Range 07
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	22.75
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 22.75
Options outstanding, number of shares (in shares) | shares	436
Options outstanding, weighted average remaining contractual life	6 years 4 months 10 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.75
Options exercisable, number of shares (in shares) | shares	436
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.75
Range 08
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	23.51
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 23.51
Options outstanding, number of shares (in shares) | shares	97
Options outstanding, weighted average remaining contractual life	6 years 9 months 22 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 23.51
Options exercisable, number of shares (in shares) | shares	97
Options exercisable, weighted average exercise price (in dollars per share)	$ 23.51
Range 09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	24.07
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 24.07
Options outstanding, number of shares (in shares) | shares	7
Options outstanding, weighted average remaining contractual life	6 years 5 months 16 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 24.07
Options exercisable, number of shares (in shares) | shares	7
Options exercisable, weighted average exercise price (in dollars per share)	$ 24.07