Class A - C000046489 Class A Class C - C000046487 Class C Class I - C000046488 Class I Class IS - C000192834 Class IS Industry Sector:1C000046489-Industrial Revenue Industrial Revenue [Member] Industry Sector:2C000046489-Transportation Transportation [Member] Industry Sector:3C000046489-Leasing Leasing [Member] Industry Sector:4C000046489-Health Care Health Care [Member] Industry Sector:5C000046489-Education Education [Member] Industry Sector:6C000046489-Special Tax Obligation Special Tax Obligation [Member] Industry Sector:7C000046489-Water & Sewer Water & Sewer [Member] Industry Sector:8C000046489-Power Power [Member] Industry Sector:9C000046489-Other Other [Member] Industry Sector:10C000046489-Local General Obligation Local General Obligation [Member] Industry Sector:11C000046489-State General Obligation State General Obligation [Member] Industry Sector:12C000046489-Housing Housing [Member] Industry Sector:13C000046489-Short-Term Investments Short-Term Investments [Member] Industry Sector:14C000046487-Industrial Revenue Industrial Revenue [Member] Industry Sector:15C000046487-Transportation Transportation [Member] Industry Sector:16C000046487-Leasing Leasing [Member] Industry Sector:17C000046487-Health Care Health Care [Member] Industry Sector:18C000046487-Education Education [Member] Industry Sector:19C000046487-Special Tax Obligation Special Tax Obligation [Member] Industry Sector:20C000046487-Water & Sewer Water & Sewer [Member] Industry Sector:21C000046487-Power Power [Member] Industry Sector:22C000046487-Other Other [Member] Industry Sector:23C000046487-Local General Obligation Local General Obligation [Member] Industry Sector:24C000046487-State General Obligation State General Obligation [Member] Industry Sector:25C000046487-Housing Housing [Member] Industry Sector:26C000046487-Short-Term Investments Short-Term Investments [Member] Industry Sector:27C000046488-Industrial Revenue Industrial Revenue [Member] Industry Sector:28C000046488-Transportation Transportation [Member] Industry Sector:29C000046488-Leasing Leasing [Member] Industry Sector:30C000046488-Health Care Health Care [Member] Industry Sector:31C000046488-Education Education [Member] Industry Sector:32C000046488-Special Tax Obligation Special Tax Obligation [Member] Industry Sector:33C000046488-Water & Sewer Water & Sewer [Member] Industry Sector:34C000046488-Power Power [Member] Industry Sector:35C000046488-Other Other [Member] Industry Sector:36C000046488-Local General Obligation Local General Obligation [Member] Industry Sector:37C000046488-State General Obligation State General Obligation [Member] Industry Sector:38C000046488-Housing Housing [Member] Industry Sector:39C000046488-Short-Term Investments Short-Term Investments [Member] Industry Sector:40C000192834-Industrial Revenue Industrial Revenue [Member] Industry Sector:41C000192834-Transportation Transportation [Member] Industry Sector:42C000192834-Leasing Leasing [Member] Industry Sector:43C000192834-Health Care Health Care [Member] Industry Sector:44C000192834-Education Education [Member] Industry Sector:45C000192834-Special Tax Obligation Special Tax Obligation [Member] Industry Sector:46C000192834-Water & Sewer Water & Sewer [Member] Industry Sector:47C000192834-Power Power [Member] Industry Sector:48C000192834-Other Other [Member] Industry Sector:49C000192834-Local General Obligation Local General Obligation [Member] Industry Sector:50C000192834-State General Obligation State General Obligation [Member] Industry Sector:51C000192834-Housing Housing [Member] Industry Sector:52C000192834-Short-Term Investments Short-Term Investments [Member] Net Assets Investment Company Portfolio Turnover Portfolio Turnover Commodity Index Linked Notes [Member] Commodity Index Linked Notes Sovereign Debt Securities [Member] Sovereign Debt Securities Convertible Debt Securities [Member] Convertible Debt Securities Corporate Debt Securities [Member] Corporate Debt Securities Corporate Note Securities [Member] Corporate Note Securities Corporate Bond Securities [Member] Corporate Bond Securities Fixed Income Investments [Member] Fixed Income Investments Securities Investment [Member] Securities Investment Other Aggregated Investments [Member] Other Aggregated Investments Real Estate Sector [Member] Real Estate Sector Standard Poors 500 Index [Member] Standard Poors 500 Index Nasdaq Composite Index [Member] Nasdaq Composite Index Equity Securities Industry [Member] Equity Securities Industry Equity Securities [Member] Equity Securities Dow Jones Industrial Average [Member] Dow Jones Industrial Average Construction Sector [Member] Construction Sector Automotive Sector [Member] Automotive Sector Transportation Sector [Member] Transportation Sector Aerospace Sector [Member] Aerospace Sector Consumer Sector [Member] Consumer Sector Chemicals Sector [Member] Chemicals Sector Insurance Sector [Member] Insurance Sector Cash [Member] Cash Asset Backed Securities [Member] Asset Backed Securities Container And PackagingSector [Member] Container And PackagingSector Investment Type [Axis] Asset Class US Treasury Securities [Member] US Treasury Securities Mortgage Backed Securities [Member] Mortgage Backed Securities Investment Type Categorization [Member] Investment Type Categorization Entertainment Sector [Member] Entertainment Sector Food And Beverage Sector [Member] Food And Beverage Sector Financial Services Sector [Member] Financial Services Sector Healthcare Sector [Member] Healthcare Sector Energy Sector [Member] Energy Sector Technology Sector [Member] Technology Sector Government Sector [Member] Government Sector No Trading Symbol