Income Taxes - Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax rate	21.00%	35.00%	35.00%
State income taxes, net of Federal tax effect	5.70%	3.80%	6.80%
Non-deductible compensation and meals and entertainment	1.00%	0.70%	1.20%
Tax credits	(2.20%)	(2.20%)	(2.10%)
Valuation allowance on foreign tax credit	0.00%	2.50%	0.00%
Enactment of TCJA	0.00%	9.10%	0.00%
Other	(0.60%)	(0.80%)	0.50%
Effective tax rate	24.90%	48.10%	41.40%