Unsecured Credit Facility (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 01, 2023	Jun. 15, 2021	Sep. 28, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date			Jun. 15, 2026
Line of Credit Facility, Interest Rate Reduction			0.01%
Line of credit facility, maximum percent for loan advances			65.00%
Debt Instrument, Alternate Basis Spread on Variable Rate	0.00%
Long-term Line of Credit	$ 0				$ 0
Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage			0.30%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			1.40%
Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage			0.10%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.70%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.775%
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,500,000	$ 1,815,000
Line of Credit, Additional Borrowing Capacity			$ 500,000
Line of Credit Borrowing Capacity Increase (Decrease)				$ 315,000
Line of Credit Facility, Interest Rate Description			At BPLP’s option, loans under the 2021 Credit Facility will bear interest at a rate per annum equal to (1) (a) in the case of loans denominated in Dollars, Term SOFR and SOFR, (b) in the case of loans denominated in Euro, EURIBOR, (c) in the case of loans denominated in Canadian Dollars, CDOR, and (d) in the case of loans denominated in Sterling, SONIA, in each case, plus a margin ranging from 70.0 to 140.0 basis points based on BPLP’s credit rating or (2) an alternate base rate equal to the greatest of (a) the Federal Funds rate plus 0.5%, (b) the administrative agent’s prime rate, (c) Term SOFR plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 40 basis points based on BPLP’s credit rating.
Line of Credit Facility, Commitment Fee Percentage	0.15%
Long-term Line of Credit	$ 0
Revolving Credit Facility [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.10%