Stock-based Compensation - Fair Value Assumptions And Methodology (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair value assumptions and methodology [Abstract]
Expected volatility range of stock, minimum (in hundredths)	39.80%	37.40%
Expected volatility range of stock, maximum (in hundredths)	40.10%	40.80%
Expected life of option, range in years	5 years	5 years
Risk-free interest rate range, minimum (in hundredths)	2.20%	1.80%
Risk-free interest rate range, maximum (in hundredths)	2.80%	1.90%
Expected dividend yield on stock, minimum (in hundredths)	0.00%	0.00%
Expected dividend yield on stock, maximum (in hundredths)	0.00%	0.00%