Stockholders' Equity - Warrants (Details)	12 Months Ended
	Dec. 31, 2017 item $ / shares shares	Jul. 12, 2017 shares
Warrants
Number of Common Stock each warrant may purchase	0.5
Exercise price of warrant per half of Common Stock | $ / shares	$ 5.75
Exercise price of warrant per one Common Stock (in US$ per share) | $ / shares	$ 11.50
Expiration of warrants from business acquisition date	5 years
Warrant redemption price (in US$ per share) | $ / shares	$ 0.01
Minimum written notice period of redemption	30 days
Minimum common stock sales price for exercise of redemption right (in US$ per share) | $ / shares	$ 24.00
Minimum trading days within 30-day period at $24 per share for exercise of redemption right | item	20
Trading day period for exercise of redemption right	30 days
Period of the 30-day period prior to notice of redemption	3 days
Period of current registration effectivity prior to 30-day trading period	5 days
Warrants
Warrants
Warrants outstanding	35,000,000	35,000,000
Warrants | IPO
Warrants
Units issued	35,000,000
Common stock included in units	1
Warrants included in units	1