FAIR VALUE - Summary of Changes in Fair Value of Level III Investments (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 19,907,890	$ 15,673,386
Transfers into Level III	1,150,232	1,998,203
Transfers out of Level III	(2,242,347)	(1,550,325)
Purchases	7,247,709	7,150,411
Sales	(6,991,638)	(5,397,631)
Realized gains (losses), net	1,449,804	950,934
Unrealized appreciation (depreciation), net	(944,195)	(1,082,912)
Ending balance	21,465,845	19,907,890
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	1,574,952	1,520,932
Corporate debt – bank debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2,253,476	1,978,637
Transfers into Level III	377,448	476,034
Transfers out of Level III	(656,354)	(547,130)
Purchases	1,673,352	1,667,292
Sales	(1,120,160)	(1,329,534)
Realized gains (losses), net	33,427	50,938
Unrealized appreciation (depreciation), net	(248,248)	42,761
Ending balance	2,809,437	2,253,476
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	198,469	(45,214)
Corporate debt – all other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3,159,051	3,155,241
Transfers into Level III	2,410	688,299
Transfers out of Level III	(327,612)	(592,397)
Purchases	428,783	953,076
Sales	(1,029,515)	(1,183,277)
Realized gains (losses), net	120,610	112,396
Unrealized appreciation (depreciation), net	(78,452)	(25,713)
Ending balance	2,432,179	3,159,051
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	165,124	23,779
Equities – common stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	8,101,051	6,164,025
Transfers into Level III	367,562	785,470
Transfers out of Level III	(1,222,610)	(306,648)
Purchases	1,437,693	1,009,258
Sales	(2,590,023)	(564,217)
Realized gains (losses), net	956,094	178,115
Unrealized appreciation (depreciation), net	349,752	(835,048)
Ending balance	6,700,015	8,101,051
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	246,039	847,098
Equities – Preferred Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	650,096	1,090,107
Transfers into Level III	387,757	6,884
Transfers out of Level III	(35,771)	(98,797)
Purchases	280,531	53,788
Sales	(316,187)	(410,261)
Realized gains (losses), net	41,553	318,498
Unrealized appreciation (depreciation), net	88,208	310,123
Ending balance	919,771	650,096
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	(42,108)	14,873
Equities – preferred stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3,946,142	2,786,862
Transfers into Level III	15,055	39,199
Transfers out of Level III	0	(5,353)
Purchases	2,200,559	1,361,920
Sales	(978,064)	(914,108)
Realized gains (losses), net	194,681	249,933
Unrealized appreciation (depreciation), net	(842,921)	(427,689)
Ending balance	6,221,294	3,946,142
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	777,549	531,768
Real estate loan portfolio
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,737,822	479,690
Transfers into Level III	0	0
Transfers out of Level III	0	0
Purchases	1,226,791	2,104,577
Sales	(866,588)	(988,399)
Realized gains (losses), net	39,755	35,650
Unrealized appreciation (depreciation), net	(231,661)	(106,304)
Ending balance	2,369,441	1,737,822
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	231,662	106,304
Swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	44,705	0
Transfers into Level III	0	2,317
Transfers out of Level III	0	0
Purchases	0	0
Sales	(91,101)	0
Realized gains (losses), net	91,070	0
Unrealized appreciation (depreciation), net	44,674	(42,388)
Ending balance	0	44,705
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	0	42,388
Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	15,547	18,824
Transfers into Level III	0	0
Transfers out of Level III	0	0
Purchases	0	500
Sales	0	(7,835)
Realized gains (losses), net	(27,386)	5,404
Unrealized appreciation (depreciation), net	(25,547)	1,346
Ending balance	13,708	15,547
Net change in unrealized appreciation (depreciation) attributable to assets still held at end of period	$ (1,783)	$ (64)