INVESTMENTS - Investments, at Fair Value (Detail) - Consolidated Funds - USD ($) $ in Thousands | 12 Months Ended |
Dec. 31, 2019 | Dec. 31, 2018 |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Real estate investments, at fair value | $ 230,741 | $ 0 |
Real estate, fair value as a percentage of investments of consolidated funds | 3.10% | 0.00% |
Investments, at fair value | $ 7,358,409 | $ 6,531,385 |
Total investments, fair value as a percentage of investments of consolidated funds | 100.00% | 100.00% |
Securities Sold Short | $ 0 | $ (2,609) |
Proceeds from securities sold short | 0 | 2,644 |
Debt securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 6,995,677 | $ 6,502,413 |
Debt, fair value as a percentage of investments of consolidated funds | 95.10% | 99.50% |
Equity securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 131,991 | $ 28,972 |
Equity securities, fair value as a percentage of investments of consolidated funds | 1.80% | 0.50% |
Securities Sold Short | $ 0 | $ (2,609) |
United States | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt securities, cost | 3,981,956 | 4,019,823 |
Equity securities, cost | 137,149 | 6,117 |
Real estate investments, at fair value | $ 230,741 | $ 0 |
Real estate, fair value as a percentage of investments of consolidated funds | 3.10% | 0.00% |
Real estate, cost | $ 230,741 | $ 0 |
United States | Debt securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 3,960,403 | $ 3,860,665 |
Debt, fair value as a percentage of investments of consolidated funds | 53.90% | 59.10% |
United States | Debt securities | Communication services | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 464,356 | $ 543,948 |
Debt, fair value as a percentage of investments of consolidated funds | 6.40% | 8.40% |
United States | Debt securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 508,701 | $ 506,551 |
Debt, fair value as a percentage of investments of consolidated funds | 6.90% | 7.80% |
United States | Debt securities | Consumer staples | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 92,102 | $ 112,197 |
Debt, fair value as a percentage of investments of consolidated funds | 1.30% | 1.70% |
United States | Debt securities | Energy | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 223,671 | $ 204,568 |
Debt, fair value as a percentage of investments of consolidated funds | 3.00% | 3.10% |
United States | Debt securities | Financials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 355,113 | $ 332,240 |
Debt, fair value as a percentage of investments of consolidated funds | 4.80% | 5.10% |
United States | Debt securities | Health care | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 512,864 | $ 537,592 |
Debt, fair value as a percentage of investments of consolidated funds | 7.00% | 8.20% |
United States | Debt securities | Industrials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 563,920 | $ 443,406 |
Debt, fair value as a percentage of investments of consolidated funds | 7.70% | 6.80% |
United States | Debt securities | Information technology | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 524,390 | $ 536,000 |
Debt, fair value as a percentage of investments of consolidated funds | 7.10% | 8.20% |
United States | Debt securities | Materials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 294,300 | $ 289,499 |
Debt, fair value as a percentage of investments of consolidated funds | 4.00% | 4.40% |
United States | Debt securities | Real estate | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 204,933 | $ 217,633 |
Debt, fair value as a percentage of investments of consolidated funds | 2.80% | 3.30% |
United States | Debt securities | Utilities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 216,053 | $ 137,031 |
Debt, fair value as a percentage of investments of consolidated funds | 2.90% | 2.10% |
United States | Equity securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 131,897 | $ 5,426 |
Equity securities, fair value as a percentage of investments of consolidated funds | 1.80% | 0.10% |
United States | Equity securities | Communication services | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 312 | $ 0 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
United States | Equity securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 658 | $ 1,915 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.10% |
United States | Equity securities | Energy | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 256 | $ 131 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
United States | Equity securities | Financials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 837 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
United States | Equity securities | Health care | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 1,348 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
United States | Equity securities | Industrials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 88 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
United States | Equity securities | Utilities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 130,671 | $ 1,107 |
Equity securities, fair value as a percentage of investments of consolidated funds | 1.80% | 0.00% |
Europe | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt securities, cost | $ 2,876,531 | $ 2,477,821 |
Equity securities, cost | 1,227 | 320 |
Europe | Debt securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 2,870,174 | $ 2,413,280 |
Debt, fair value as a percentage of investments of consolidated funds | 39.00% | 36.90% |
Europe | Debt securities | Communication services | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 469,822 | $ 530,337 |
Debt, fair value as a percentage of investments of consolidated funds | 6.40% | 8.10% |
Europe | Debt securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 659,001 | $ 545,324 |
Debt, fair value as a percentage of investments of consolidated funds | 9.00% | 8.30% |
Europe | Debt securities | Consumer staples | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 178,609 | $ 160,406 |
Debt, fair value as a percentage of investments of consolidated funds | 2.40% | 2.50% |
Europe | Debt securities | Energy | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 11,316 | $ 15,260 |
Debt, fair value as a percentage of investments of consolidated funds | 0.20% | 0.20% |
Europe | Debt securities | Financials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 101,933 | $ 48,545 |
Debt, fair value as a percentage of investments of consolidated funds | 1.40% | 0.70% |
Europe | Debt securities | Health care | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 579,765 | $ 418,516 |
Debt, fair value as a percentage of investments of consolidated funds | 7.90% | 6.40% |
Europe | Debt securities | Industrials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 362,120 | $ 246,640 |
Debt, fair value as a percentage of investments of consolidated funds | 4.90% | 3.80% |
Europe | Debt securities | Information technology | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 177,152 | $ 194,988 |
Debt, fair value as a percentage of investments of consolidated funds | 2.40% | 3.00% |
Europe | Debt securities | Materials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 230,289 | $ 221,660 |
Debt, fair value as a percentage of investments of consolidated funds | 3.10% | 3.40% |
Europe | Debt securities | Real estate | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 96,315 | $ 30,045 |
Debt, fair value as a percentage of investments of consolidated funds | 1.30% | 0.50% |
Europe | Debt securities | Utilities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 3,852 | $ 1,559 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.00% |
Europe | Equity securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 94 | $ 986 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.10% |
Europe | Equity securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 94 | $ 0 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | |
Europe | Equity securities | Consumer staples | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 38 |
Equity securities, fair value as a percentage of investments of consolidated funds | | 0.00% |
Europe | Equity securities | Health care | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | 0 | $ 948 |
Equity securities, fair value as a percentage of investments of consolidated funds | | 0.10% |
Asia and other | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt securities, cost | 164,650 | $ 233,603 |
Equity securities, cost | 0 | 22,977 |
Asia and other | Debt securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 165,100 | $ 228,468 |
Debt, fair value as a percentage of investments of consolidated funds | 2.20% | 3.50% |
Asia and other | Debt securities | Communication services | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 15,750 | $ 12,069 |
Debt, fair value as a percentage of investments of consolidated funds | 0.20% | 0.20% |
Asia and other | Debt securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 40,073 | $ 36,822 |
Debt, fair value as a percentage of investments of consolidated funds | 0.50% | 0.60% |
Asia and other | Debt securities | Consumer staples | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 11,545 | $ 11,867 |
Debt, fair value as a percentage of investments of consolidated funds | 0.20% | 0.20% |
Asia and other | Debt securities | Energy | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 13,471 | $ 20,594 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.30% |
Asia and other | Debt securities | Financials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 10,313 | $ 13,995 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.20% |
Asia and other | Debt securities | Government | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 917 | $ 12,155 |
Debt, fair value as a percentage of investments of consolidated funds | 0.00% | 0.20% |
Asia and other | Debt securities | Health care | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 8,923 | $ 9,633 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.10% |
Asia and other | Debt securities | Industrials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 31,814 | $ 40,468 |
Debt, fair value as a percentage of investments of consolidated funds | 0.40% | 0.70% |
Asia and other | Debt securities | Information technology | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 5,639 | $ 1,887 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.00% |
Asia and other | Debt securities | Materials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 5,604 | $ 15,516 |
Debt, fair value as a percentage of investments of consolidated funds | 0.10% | 0.20% |
Asia and other | Debt securities | Real estate | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 751 | $ 38,592 |
Debt, fair value as a percentage of investments of consolidated funds | 0.00% | 0.60% |
Asia and other | Debt securities | Utilities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Debt, fair value | $ 20,300 | $ 14,870 |
Debt, fair value as a percentage of investments of consolidated funds | 0.30% | 0.20% |
Asia and other | Equity securities | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 22,560 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.30% |
Asia and other | Equity securities | Consumer discretionary | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 874 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
Asia and other | Equity securities | Consumer staples | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 997 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
Asia and other | Equity securities | Energy | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 382 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
Asia and other | Equity securities | Financials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 2,935 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
Asia and other | Equity securities | Industrials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 11,265 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.20% |
Asia and other | Equity securities | Information technology | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 1,725 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.00% |
Asia and other | Equity securities | Materials | | |
Schedule Of Investments In Marketable Securities [Line Items] | | |
Equity securities, fair value | $ 0 | $ 4,382 |
Equity securities, fair value as a percentage of investments of consolidated funds | 0.00% | 0.10% |