Related Party Transactions (Narrative) (Details) - USD ($)	1 Months Ended						9 Months Ended	12 Months Ended
	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Other long-term investments	$ 551,931,000		$ 182,157,000					$ 551,931,000	$ 182,157,000
Net investment income								338,370,000	139,430,000	$ 164,011,000
Contributed capital							$ 860,573,000	860,573,000	0	0
Prudential Insurance
Related Party Transaction [Line Items]
Stock option program plan expense								100,000	100,000	100,000
Deferred compensation program expense								800,000	600,000	1,000,000
Pension plan expense								1,000,000	1,000,000	1,000,000
Welfare plan expense								$ 2,000,000	2,000,000	3,000,000
Defined contribution plan employer matching contribution percent								4.00%
Defined contribution plan, cost recognized								$ 500,000	500,000	700,000
Affiliated Entity
Related Party Transaction [Line Items]
Accrued interest receivable related to long-term notes	100,000		100,000					100,000	100,000
Revenue related to long-tern notes receivable								900,000	1,000,000	1,000,000
Interest expense related to loans payable								53,000,000	0	0
Affiliated Entity | PAIST
Related Party Transaction [Line Items]
Allocated lease expense								4,000,000	4,000,000	4,000,000
Allocated sub-lease rental income								0	0	1,000,000
Affiliated Entity | PAD
Related Party Transaction [Line Items]
Commissions and fees								108,000,000	143,000,000	177,000,000
Affiliated Entity | ASTISI and Prudential Investments
Related Party Transaction [Line Items]
Revenue administrative sharing agreement								112,000,000	173,000,000	221,000,000
Affiliated Entity | PGIM
Related Party Transaction [Line Items]
Net investment income								11,000,000	5,000,000	6,000,000
Prudential Financial Joint Ventures
Related Party Transaction [Line Items]
Other long-term investments	102,000,000		45,000,000					102,000,000	45,000,000
Net investment income								5,000,000	100,000	2,000,000
Prudential Financial
Related Party Transaction [Line Items]
Line of credit facility, maximum borrowing capacity	9,000,000,000							9,000,000,000
PAI
Related Party Transaction [Line Items]
Contributed capital		$ 8,422,000,000							0	0
Return of capital	$ 1,140,000,000
Dividends					$ 267,000,000	$ 75,000,000
Prudential Financial
Related Party Transaction [Line Items]
Contributed capital								8,421,955,000	$ 0	$ 0
Return of capital								$ (1,140,000,000)
Dividends			$ 180,000,000	$ 270,000,000