Related Party Transactions (Narrative) (Details)		3 Months Ended					9 Months Ended
		Sep. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2018 USD ($) policy	Sep. 30, 2017 USD ($)
Related Party Transaction [Line Items]
Commissions and fees		$ 106,926,000			$ 129,105,000		$ 405,085,000	$ 140,940,000
Other invested assets	[1]	333,382,000		$ 263,074,000			333,382,000
Net investment income		86,186,000			86,522,000		245,750,000	267,178,000
Fee income from revenue sharing agreement		3,727,000			4,555,000		10,744,000	13,132,000
Prudential Insurance
Related Party Transaction [Line Items]
Proceeds from Contributions from Affiliates			$ 6,000,000		149,000,000	$ 5,000,000
Dividends				250,000,000			0
Prudential Insurance
Related Party Transaction [Line Items]
Stock option program plan expense		300,000			200,000		1,000,000	900,000
Deferred compensation program expense		1,000,000			2,000,000		6,000,000	7,000,000
Pension plan expense		5,000,000			6,000,000		17,000,000	19,000,000
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		2,000,000			3,000,000		$ 7,000,000	8,000,000
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		3,884,000,000		3,688,000,000			$ 3,884,000,000
Fees related to Life Insurance, Corporate or Bank Owned, amount		11,000,000			11,000,000		34,000,000	34,000,000
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			17,000,000		$ 54,000,000	49,000,000
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		900,000		1,000,000			$ 900,000
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
Interest expense related to loans payable		200,000			100,000		600,000	700,000
Affiliated Entity | PAD
Related Party Transaction [Line Items]
Commissions and fees		191,000,000			150,000,000		554,000,000	465,000,000
Affiliated Entity | ASTISI and PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement		85,000,000			82,000,000		252,000,000	239,000,000
Affiliated Entity | PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement		3,000,000			4,000,000		7,000,000	11,000,000
Affiliated Entity | PGIM
Related Party Transaction [Line Items]
Net investment income		3,000,000			4,000,000		10,000,000	11,000,000
Prudential Financial Joint Ventures
Related Party Transaction [Line Items]
Other invested assets		95,000,000		$ 79,000,000			95,000,000
Net investment income		$ 2,000,000			$ 1,000,000		$ 4,000,000	$ 7,000,000

[1] Prior period amounts have been reclassified to conform to current period presentation. See "Adoption of ASU 2016-01" in Note 2 for details