Common Shares [Member] Stock that is subordinate to all other stock of the issuer. Developing Industries Risk [Member] Energy Infrastructure Sector Risk [Member] Energy Infrastructure Sector Risk [Member] Fee For Open Market Purchases Of Common Shares [Member] Fee For Open Market Purchases Of Common Shares [Member] Fee For Optional Common Shares Purchases [Member] Fee for Optional Common Shares Purchases [Member] Preferred Shares [Member] Preferred shares may provide a preferential dividend to the dividend on common stock and may take precedence over common stock in the event of a liquidation. Preferred shares typically represent an ownership interest in the company. Sales Of Common Shares Held In Dividend Reinvestment Account [Member] Sales of Common Shares Held in Dividend Reinvestment Account [Member] Utility Sector Risk [Member] Utility Sector Risk [Member] Class of Stock [Domain] Debt Instrument Name [Domain]