Related Party Transactions (Narrative) (Details)	3 Months Ended					9 Months Ended
	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2017 USD ($) policy	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Apr. 01, 2016 USD ($)
Related Party Transaction [Line Items]
Other long-term investments	$ 312,683,000					$ 312,683,000		$ 344,463,000
Net investment income	86,522,000		$ 103,743,000			267,178,000	$ 287,814,000
Contributed capital						148,500,000	405,321,000
Prudential Insurance
Related Party Transaction [Line Items]
Contributed capital	149,000,000	$ 5,000,000		$ 200,000,000	$ 5,000,000	153,500,000	205,000,000
Dividend				$ 2,594,000,000		0
Prudential Insurance
Related Party Transaction [Line Items]
Stock option program plan expense	200,000		300,000			900,000	900,000
Deferred compensation program expense	2,000,000		2,000,000			7,000,000	6,000,000
Pension plan expense	6,000,000		6,000,000			19,000,000	17,000,000
Welfare plan expense	7,000,000		7,000,000			$ 21,000,000	21,000,000
Defined contribution plan, employer matching contribution, percent (up to)						4.00%
Defined contribution plan, cost recognized	3,000,000		2,000,000			$ 8,000,000	7,000,000
Number of Corporate Owned Life Insurance policies sold | policy						5
Prudential Insurance and Prudential Financial
Related Party Transaction [Line Items]
Life Insurance, Corporate or Bank Owned, amount	3,666,000,000					$ 3,666,000,000		3,367,000,000
Fees related to Life Insurance, Corporate or Bank Owned, amount	11,000,000		10,000,000			34,000,000	31,000,000
Maximum amount of mortality risk	3,500,000					3,500,000
Prudential Financial
Related Party Transaction [Line Items]
Company's share of corporate expenses	17,000,000		15,000,000			$ 49,000,000	43,000,000
Number of Corporate Owned Life Insurance policies sold | policy						1
Affiliated Entity
Related Party Transaction [Line Items]
Accrued interest receivable related to long-tern notes receivable	1,000,000					$ 1,000,000		1,000,000
Revenues related to long-term notes receivable	1,000,000		1,000,000			4,000,000	4,000,000
Line of credit facility, maximum borrowing capacity	2,200,000,000.0					2,200,000,000.0
Prepaid debt									$ 125,000,000
Interest expense related to loans payable	100,000		0			700,000	13,000,000
Affiliated Entity | PAD
Related Party Transaction [Line Items]
Commissions and fees	150,000,000		182,000,000			465,000,000	546,000,000
Affiliated Entity | ASTISI and PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement	82,000,000		76,000,000			239,000,000	218,000,000
Affiliated Entity | PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement	4,000,000		3,000,000			11,000,000	10,000,000
Affiliated Entity | PGIM
Related Party Transaction [Line Items]
Net investment income	4,000,000		3,000,000			11,000,000	12,000,000
Prudential Financial Joint Ventures
Related Party Transaction [Line Items]
Other long-term investments	76,000,000					76,000,000		$ 100,000,000
Net investment income	$ 1,000,000		$ 3,000,000			$ 7,000,000	$ (100,000)