Income Taxes (Additional Disclosures) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Operating loss carryforwards			$ 68,900,000
Deferred tax assets, operating loss carryforwards, subject to expiration			49,600,000
Deferred tax assets, operating loss carryforwards, not subject to expiration			19,300,000
Provisional expense for the effects of the 2017 Tax Act		$ 7,300,000
Provisional expense for remeasurement of net deferred tax assets for the effects of the 2017 Tax Act		5,500,000
Provisional expense for unrepatriated earnings from foreign subsidiaries for the effects of the 2017 Tax Act		200,000
Provisional expense for limitations on the deductibility of executive compensation for the effects of the 2017 Tax Act		$ 1,600,000
Valuation allowance			19,878,000	$ 4,042,000	$ 15,500,000
Increase (decrease) in valuation allowance	$ (11,500,000)
Net deferred tax assets	$ 18,700,000		36,000	$ 18,663,000
Unremitted earnings outside the US			2,300,000
Unrecognized tax benefits			$ 0