Alcentra Acquisition - Summarizes of Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands			12 Months Ended
		Jan. 31, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Realized loss on asset acquisition	[1]		$ (3,825)
Alcentra Acquisition
Business Acquisition [Line Items]
Common stock issued by the Company		$ 101,963
Cash Consideration paid by the Company		9,043
Transaction costs		7,250
Total Purchase Price		118,256
Investment portfolio		195,682
Cash		3,409
Portfolio receivables		1,003
Other receivable		395
InterNotes		50,271
Secured credit facility		(34,558)
Borrowing expense payable		(834)
Other payables		(395)
Net assets acquired		114,431
Realized loss on asset acquisition		$ (3,825)

[1] After the close of business on January 31, 2020, in connection with the Alcentra Acquisition (as defined in Note 1 and further discussed in Note 14), the Company acquired net assets of $114,431 which included $195,682 of investments, $3,409 cash and cash equivalents and $1,398 of other assets, net of $86,058 of assumed liabilities, for the total cash and stock consideration of $118,256, inclusive of $7,250 of asset acquisition costs.