RELATED PARTY TRANSACTIONS (Details) - USD ($)			9 Months Ended
	Jun. 19, 2017	Apr. 04, 2017	Dec. 31, 2017
Related Party Loans
Exercise price of warrants (in dollars per share)			$ 1.00
Initial Stockholders
Founder Shares
Percentage of shares held by related party			20.00%
Holding period of founder shares			1 year
Affiliate of Sponsor | Administrative Support Agreement
Administrative Support Agreement
Monthly service fees			$ 10,000
Service fees incurred			60,000
Maximum
Related Party Loans
Conversion of working capital loan to warrants			$ 2,000,000
Class A Common Stock
Founder Shares
Aggregated shares issued			1,651,075
Related Party Loans
Number of warrants issued in exchange for working capital loan			2,000,000
Class A Common Stock | Initial Stockholders
Founder Shares
Stock price threshold that allows transfer of shares			$ 12.00
Number of trading days within 30 days required for the transfer, assignment or sale of shares			20 days
Period over which the required trading days of shares at $12.00 per share or over had to occur			30 days
Minimum period after initial business combination to allow transfer of founders shares			150 days
Class F Common Stock
Founder Shares
Aggregated shares issued	11,500,000		11,500,000
Number of shares transferred to the independent directors	25,000
Founder Shares Maximum Number of Shares Subject to Forfeiture to Maintain Percentage of Issued and Outstanding Shares Held by Initial Stockholders			1,500,000
Class F Common Stock | Common Stock
Founder Shares
Number of shares issued (in shares)			11,500,000
Class F Common Stock | Federal Street Sponsor LLC
Founder Shares
Aggregated shares issued		10,062,500
Stock dividend shares	1,437,500
Proceeds from issuance of common stock		$ 25,000
Founder shares aggregate (in shares)			1,500,000
IPO | Federal Street Sponsor LLC | Promissory Note
Related Party Loans
Maximum borrowing capacity			$ 250,000