PRIVATE PLACEMENT (Details) - USD ($)		6 Months Ended
	Jul. 24, 2017	Sep. 30, 2017
Private Placement Warrants
Proceeds from sale of Private Placement Warrants		$ 14,950,000
Warrant price (in dollars per share)		$ 1.00
Class A Common Stock
Private Placement Warrants
Warrant price (in dollars per share)	$ 11.50
Private Placement
Private Placement Warrants
Warrants Issued	14,950,000
Proceeds from sale of Private Placement Warrants	$ 14,950,000
Warrant price (in dollars per share)	$ 1.00
Federal Street Sponsor LLC | Private Placement
Private Placement Warrants
Warrants Issued	14,950,000
Proceeds from sale of Private Placement Warrants	$ 14,950,000
Warrant price (in dollars per share)	$ 1.00
Number of shares issuable for each warrant	1
Federal Street Sponsor LLC | Private Placement | Class A Common Stock
Private Placement Warrants
Warrant price (in dollars per share)	$ 11.50