Asset Based Finance Investments Risk [Member] Asset Based Finance Investments Risk [Member] Banking Risk [Member] Banking Risk [Member] This member stands for Common Stocks. Common Stocks [Member] Conflicts Of Interest Risk [Member] Conflicts Of Interest Risk [Member] Counterparty Risk [Member] Counterparty Risk [Member] Credits Risk [Member] Credits Risk [Member] Credit Risk [Member] Currency Risk [Member] Currency Risk [Member] Derivatives Risk [Member] Derivatives Risk [Member] Fair Valuation Of Portfolio Investments Risk [Member] Fair Valuation Of Portfolio Investments Risk [Member] Global Risks [Member] Global Risks [Member] Hedging Risk [Member] Hedging Risk [Member] High Yield Investment Risk [Member] High Yield Investment Risk [Member] Incentive Fee Risk [Member] Incentive Fee Risk [Member] Infrastructure Sector Risk [Member] Infrastructure Sector Risk [Member] Interest Rate Risk [Member] Interest Rates Risk [Member] Interest Rates Risk [Member] Investing In Collateralized Loan Obligations And Other Structured Debt Securities Risk [Member] Investing In Collateralized Loan Obligations And Other Structured Debt Securities Risk [Member] Key Personnel Risk [Member] Key Personnel Risk [Member] Leverage Risk [Member] Leverage Risk [Member] Limited Investment Opportunities Risk [Member] Limited Investment Opportunities Risk [Member] Liquidity Risk [Member] Liquidity Risk [Member] Loan Accumulation Facilities Risk [Member] Loan Accumulation Facilities Risk [Member] London Interbank Offered Rate Risk [Member] London Interbank Offered Rate Risk [Member] Market Risk [Member] Market Risk [Member] Non-diversification Risk [Member] Non-Diversification Risk [Member] Non Diversification Risk [Member] Non United States Investing Risk [Member] Non United States Investing Risk [Member] Non-U.S. Investing Risk [Member] Notes Due 2028 At 6.6875 Percent [Member] 6.6875% Notes Due 2028 [Member] Notes Due 2028 At 6.6875 Percent [Member] 5.375% Notes Due 2029 [Member] Notes Due 2029 At 5.375 Percent [Member] Notes Due 2029 At 5.375 Percent [Member] Notes Due 2030 At 7.75 Percent [Member] Notes Due 2030 At 7.75 Percent [Member] 7.75% Notes due 2030 [Member] Notes Due 2031 At 6.75 Percent [Member] Notes Due 2031 At 6.75 Percent [Member] 6.75% Notes Due 2031 [Member] This member stands for Preferred Stock. Preferred Stocks [Member] Preferred Stock [Member] Preferred Stock [Member] Prepayments Risk [Member] Prepayments Risk [Member] Prepayment Risk [Member] Price Risk [Member] Price Risk [Member] Real Estate Investment Related Risks [Member] Real Estate Investment Related Risks [Member] Refinancing Risk [Member] Refinancing Risk [Member] Regulatory Capital Relief Investments Risk [Member] Regulatory Capital Relief Investments Risk [Member] Reinvestment Risk [Member] Reinvestment Risk [Member] Risks Of Default On Underlying Assets [Member] Risks Of Default On Underlying Assets [Member] Risks Relating To Convertible Perpetual Preferred Shares Conversion Feature [Member] Risks Relating To The Convertible Perpetual Preferred Shares Conversion Feature [Member] Russia Risk [Member] Russia Risk [Member] Series 2020 Notes [Member] Series 2020 Notes [Member] Series Aa Convertible Perpetual Preferred Stock [Member] This member stands for Series AA Convertible Perpetual Preferred Stock. 7.00% Series AA Convertible Perpetual Preferred Stock [Member] Series Ab Convertible Perpetual Preferred Stock [Member] This member stands for Series AB Convertible Perpetual Preferred Stock. 7.00% Series AB Convertible Perpetual Preferred Stock [Member] Series A Term Preferred Stock [Member] Series A Term Preferred Stock [Member] 6.50% Series C Term Preferred Stock due 2031 [Member] Series C Term Preferred Stock [Member] This member stands for Series C Term Preferred Stock. 6.50% Series C Term Preferred Stock due 2031 [Member] Series D Preferred Stocks [Member] 6.75% Series D Preferred Stock [Member] 6.75% Series D Preferred Stock [Member] This member stands for Series D Preferred Stock. This member stand for 8.00% Series F Term Preferred Stock due 2029 8.00% Series F Term Preferred Stock due 2029[Member] Series F Term Preferred Stock Due 2029 [Member] Subordinated Securities Risk [Member] Subordinated Securities Risk [Member] Synthetic Investments Risk [Member] Synthetic Investments Risk [Member] Tax Risk [Member] Tax Risk [Member] Information about the Unsecured Notes. Unsecured Notes [Member] Amendment Flags Class of Stock [Domain] Debt Instrument, Name [Domain]