Fair Value - Changes in Fair Value in Financial Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	$ 4,033,562	$ 3,362,940
Elimination of investments attributable to consolidation of VIEs	(14,620)	(3,902)
Fees	61,728	22,001
Purchases	265,934	385,618
Sale of investments/Distributions	(181,519)	(249,952)
Net realized losses	(954)	(4,442)
Changes in net unrealized gains	255,124	50,989
Transfer into Level III	141,353	272,593
Transfer out of Level III	(309,942)	(338,294)
Balance, End of Period	4,250,666	3,497,551
Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	14,039
Parent
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	223,550	52,342
Parent | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0	0
Consolidated Variable Interest Entities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	1,919,537	1,643,465
Elimination of investments attributable to consolidation of VIEs	(14,620)	(3,902)
Purchases	265,063	384,161
Sale of investments/Distributions	(181,435)	(186,861)
Net realized losses	(954)	(4,442)
Changes in net unrealized gains	17,535	(1,353)
Transfer into Level III	141,353	272,593
Transfer out of Level III	(309,028)	(337,673)
Balance, End of Period	1,837,451	1,765,988
Consolidated Variable Interest Entities | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	14,491	(8,655)
Consolidated Variable Interest Entities | Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0
AAA Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	1,942,051	1,666,448
Sale of investments/Distributions		(62,189)
Changes in net unrealized gains	205,364	47,770
Balance, End of Period	2,147,415	1,652,029
AAA Investments | Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0
AAA Investments | Parent | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	205,364	47,770
AAA Investments | Consolidated Variable Interest Entities | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0	0
Investments Fair Value Held By Senior Loan Fund
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	892	590
Purchases		22
Sale of investments/Distributions	(6)
Changes in net unrealized gains	28	9
Transfer out of Level III	(914)	(621)
Balance, End of Period	0	0
Investments Fair Value Held By Senior Loan Fund | Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0
Investments Fair Value Held By Senior Loan Fund | Parent | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	28	9
Investments Fair Value Held By Senior Loan Fund | Consolidated Variable Interest Entities | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0	0
Investments In HFA And Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	40,373	50,311
Purchases	871	1,435
Sale of investments/Distributions	(78)	(902)
Changes in net unrealized gains	18,158	4,563
Balance, End of Period	59,324	55,407
Investments In HFA And Other | Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0
Investments In HFA And Other | Parent | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	18,158	4,563
Investments In HFA And Other | Consolidated Variable Interest Entities | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0	0
Athene And AAA Derivative
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	130,709	2,126
Fees	61,728	22,001
Changes in net unrealized gains	14,039
Balance, End of Period	206,476	24,127
Athene And AAA Derivative | Other Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	14,039
Athene And AAA Derivative | Parent | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	0	0
Athene And AAA Derivative | Consolidated Variable Interest Entities | Net Gains (Losses) from Investment Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in net unrealized gains	$ 0	$ 0