N R not rated [Member] N A not applicable [Member] BB or Lower [Member] Investments Purchased with Collateral from Securities Lending [Member] Variable Rate Senior Loan Interests [Member] C000015080 [Member] Class I C000015078 [Member] Class C C000015076 [Member] Class A Collateralized Mortgage-Backed Securities [Member] Asset-Backed Securities [Member] Preferred Stock [Member] Common Stock [Member] Sovereign Debt [Member] Exchange Traded Funds [Member] Repurchase Agreements [Member] Corporate Bond Securities [Member] Standard & Poor's, BBB Rating [Member] Standard & Poor's, A Rating [Member] Standard & Poor's, AA Rating [Member] BRAZIL CANADA CHILE ISRAEL MEXICO SAUDI ARABIA SOUTH AFRICA UNITED KINGDOM UNITED STATES Standard & Poor's, AAA Rating [Member] US Government Corporations and Agencies Securities [Member] TÜRKIYE Turkey C000015185 [Member] C000015187 [Member] C000151934 [Member] Class R6 C000015189 [Member] Other [Member] Investment Type [Axis] Net Assets Investment Company Portfolio Turnover No Trading Symbol Flag