Combined Statement of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Statement Of Cash Flows [Abstract]
Change in fair value of warrant liabilities related party	$ 59,031	$ 0
Change in fair value of convertible promissory notes related party	1,053	22
Related parties prepaid expenses and other assets current	17	8
Related parties accounts payable and accrued expenses	186	32
Related parties accrued interest	$ 483	$ 13