Income Taxes (Effective Income Tax Expense (Benefit) Rate) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax [Line Items]
Federal statutory tax expense (benefit) rate	21.00%	35.00%	35.00%
State tax expense (benefit), net of federal benefit	17.00%	(6.00%)	19.40%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	0.00%	(168.80%)	0.00%
Effective Income Tax Rate Reconciliation Change in Deferred Tax Assets, Valuation Allowance Due to Tax Rate Change	0.00%	168.80%	0.00%
Valuation allowances	(31.70%)	(33.00%)	(25.00%)
Effective Income Tax Rate Reconciliation Change in Deferred Tax Assets, Valuation Allowance Due to Foreign Taxes	(138.30%)	0.50%	(0.10%)
Effective Income Tax Rate Reconciliation, Decrease in foreign NOL Due to Change In Ownership	202.30%	0.00%	0.00%
Foreign taxes	6.60%	(2.00%)	(0.60%)
Change in unrecognized tax benefits	(8.00%)	5.10%	(0.10%)
Effective Income Tax Rate Reconciliation Nondeductible Expense Disallowed Compensation	7.70%	(0.60%)	0.90%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent	(1.50%)	(0.90%)	2.20%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent	1.40%	(0.80%)	2.00%
Effective Tax Rate Reconciliation, Merger Related Fees/Expense	12.70%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Depletion In Excess Of Basis	(4.00%)	0.00%	0.00%
Permanent differences and other items	1.30%	0.30%	0.60%
Effective income tax expense (benefit) rate	86.50%	(2.40%)	34.30%