Fair Value of Financial Instruments Table of Level 3 Rollforward, Assets Measured on Recurring Basis Utilizing Level 3 Inputs (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value,measurement with unobservable inputs reconciliation,changes in unrealized gains included in earnings related to assets still held at period end		$ 2,123	$ 162
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		239,944	11,577
Net realized gains/(losses)		17,185	11,469
Net unrealized gains/(losses)		7,623	677
Purchases		38,053	37,234
Sales		(55,786)	(1,437)
Issuances		1,400	2
Transfers into Level 3	[1]	86,170	71,547
Transfer adjustments (out of) Level 3	[1]	(28,572)	(12,354)
Balance at end of period		191,623	117,898
PFG
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value,measurement with unobservable inputs reconciliation,changes in unrealized gains included in earnings related to assets still held at period end			0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period			3,771,458
Purchases			141,292
Sales			(3,967,798)
Attributable to policyowner			55,048
Balance at end of period			0
Primary beneficiary
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value,measurement with unobservable inputs reconciliation,changes in unrealized gains included in earnings related to assets still held at period end		10,372	(1,020)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		520,892	576,811
Net realized gains/(losses)		534	698
Net unrealized gains/(losses)		15,067	(4,306)
Purchases		77,373	13,625
Sales		(78,206)	(63,214)
Issuances		1,436	550
Transfers into Level 3	[1]	118,718	136,806
Transfer adjustments (out of) Level 3	[1]	(66,215)	(152,636)
Balance at end of period		693,697	179,923
Other real estate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfer adjustments (out of) Level 3		(10,296)	(817)
CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfer adjustments (out of) Level 3		(104,098)
CLOs | Primary beneficiary
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers into Level 3		$ 104,098
Assets of Consolidated CLOs | Primary beneficiary
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Adoption of ASU 2015-02			$ (328,411)

[1] All transfers are deemed to occur at end of period. Transfers between Level 2 and 3 were a result of subjecting third-party pricing on both CLO and Non-CLO assets to various liquidity, depth, bid-ask spread and benchmarking criteria as well as assessing the availability of observable inputs affecting their fair valuation.