Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 28, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes Disclosure [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent				21.00%	34.00%
Deferred tax balance recorded		$ 1,700,000		$ 1,700,000	$ 1,704,000
Provision for income taxes					0
Transition tax liability	$ 0		$ 0	0
Foreign tax effects measurement period adjustments			0	0
Deferred tax asset valuation allowance	5,590,000	2,505,000		5,590,000	$ 2,505,000	$ 2,650,000	$ 2,349,000
Change in deferred tax asset valuation allowance				3,100,000
ASU 2018-02 [Member]
Income Taxes Disclosure [Line Items]
Amount reclassified to retained earnings	$ 300,000			$ 300,000
Maximum [Member]
Income Taxes Disclosure [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent					35.00%
Earnings of foreign subsidiaries		$ 0	$ 0		$ 0