Income Taxes (Reconciliation of Effective Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21.00%	35.00%	35.00%
State income taxes, net of federal benefit	0.80%	(3.20%)	2.50%
Non-U.S. income taxed at different rates	0.80%	(4.30%)	(0.60%)
(Increase) decrease in valuation allowance	(3.60%)	0.10%	(0.20%)
Impact of 2017 Tax Cuts and Jobs Act	0	(0.642)	0
Net operating loss carryback adjustment	0.00%	0.00%	(4.70%)
Reduction in tax benefit related to stock-based awards	(1.00%)	(16.90%)	0.00%
Non-deductible expenditures and goodwill	(9.00%)	(3.90%)	(6.10%)
Research and development credit	0.30%	3.60%	5.70%
Other	(0.40%)	0.10%	1.50%
Effective income tax rate	8.90%	(53.70%)	33.10%