Stock-Based Compensation (Additional Information on Options) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding, Weighted Average Remaining Contractual Life (years)	1 year 4 months 13 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	1 year 4 months 13 days
Options Outstanding, Weighted Average Remaining Contractual Life (years), Vested or Expected to vest	1 year 4 months 13 days
Closing Stock Price Used to Calculate Intrinsic Value	$ 151.31
Range One [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Expected exercise price:	57.28
Exercise price range, lower range limit	57.28
Exercise price range, upper range limit	$ 59.35
Options Outstanding, Number of Options | shares	37,269
Options Outstanding, Weighted Average Exercise Price	$ 57.28
Options Outstanding, Aggregate Intrinsic Value | $	$ 3.5
Options Exercisable, Exercisable Shares | shares	37,269
Options Exercisable, Weighted Average Exercise Price	$ 57.28
Options Exercisable, Aggregate Intrinsic Value | $	$ 3.5
Option Outstanding, Number of Options, Vested or Expected to Vest | shares	37,269
Options Outstanding, Weighted Average Exercise Price, Vested or Expected to Vest	$ 57.28
Options Outstanding, Average Intrinsic Value, Vested or Expected to Vest | $	$ 3.5