Active Management Risk [Member] Changing Distribution Level Risk [Member] Convertible Securities Risk [Member] Counterparty Risk [Member] Credit Risk [Member] Derivatives Risks [Member] Derivatives Risk Futures Contracts Risk [Member] Emerging Market Securities Risk [Member] Foreign Securities Risk [Member] Frequent Trading Risk [Member] High Yield Investments Risk [Member] Issuer Risk [Member] Large Cap Stock Risk [Member] Leverage Risk [Member] Liquidity Risk [Member] Market Risks [Member] Preferred Stock Risk [Member] Quantitative Models Risk [Member] Rule 144A and Other Exempted Securities Risk [Member] Sector Risk [Member] Unrated Securities Risk [Member] Transactions in Derivatives [Member] Preferred Shares [Member] Common Shares [Member]