Label	Element	Value
8.95% 2031 Notes [Member] \| Subsequent Event [Member]
Senior Securities Amount	cef_SeniorSecuritiesAmt	$ 300,000,000
3.437 2028 Notes [Member] \| Subsequent Event [Member]
Senior Securities Amount	cef_SeniorSecuritiesAmt	219,803,000
3.364 2026 Notes [Member] \| Subsequent Event [Member]
Senior Securities Amount	cef_SeniorSecuritiesAmt	263,220,000
5.50% 2030 Notes [Member] \| Subsequent Event [Member]
Senior Securities Amount	cef_SeniorSecuritiesAmt	164,068,000
Prospect Capital InterNotes [Member] \| Subsequent Event [Member]
Senior Securities Amount	cef_SeniorSecuritiesAmt	$ 594,554,000
Common Stock [Member] \| Subsequent Event [Member]
Outstanding Security, Authorized [Shares]	cef_OutstandingSecurityAuthorizedShares	3,236,996,787
Outstanding Security, Held [Shares]	cef_OutstandingSecurityHeldShares	556,989,222
Preferred Stock [Member] \| Subsequent Event [Member]
Outstanding Security, Authorized [Shares]	cef_OutstandingSecurityAuthorizedShares	763,003,213
Outstanding Security, Held [Shares]	cef_OutstandingSecurityHeldShares	66,410,432