Income Taxes - Schedule of Operating Loss and Tax Credit Carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Contributions (expiring through 2024)	$ 48,531
Federal
Operating Loss Carryforwards [Line Items]
Net operating losses	48,531	$ 45,081
Disallowed interest expense (no expiration)	17,783	5,018
Contributions (expiring through 2024)	658	524
Research tax credits (expiring through 2026)	1,342	135
State | New Jersey (expiring in 2039)
Operating Loss Carryforwards [Line Items]
Net operating losses	4,942	2,976
State | Other states (expiring through 2039)
Operating Loss Carryforwards [Line Items]
Net operating losses	3,266	2,307
State | New Jersey research credits (expiring in 2026)
Operating Loss Carryforwards [Line Items]
Net operating losses	764	0
Foreign
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 0	$ 257