Valuation Allowances on Deferred Tax Assets and Recently Enacted Tax Reform (10Q) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	$ 1,500	$ 3,500	$ 5,700	$ 13,200
Net Interest Expense Deduction Limit, Tax Reform Act, Disallowed Deduction			$ 14,100
U.S. Corporate Income Tax Rate, Previously in Effect			35.00%
U.S. corporate income tax rate, as amended			21.00%
Net Interest Expense Deduction Limit of Adjusted Gross Income, Tax Reform Act			30.00%
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	95,200		$ 95,200
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 11,800		$ 11,800
Loss Generated Through 2017 [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Statutory Carryforward Period			20 years
Loss Generated Through 2016 [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Statutory Carryforward Period			12 years
Loss Generated After 2017 [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Limit of Taxable Income, Tax Reform Act, Provisions in Effect			80.00%
Minimum [Member] | Loss Generated Through 2017 [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date			Dec. 31, 2030
Maximum [Member] | Loss Generated Through 2017 [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date			Dec. 31, 2037