Related Party Transactions (Narrative) (Details)		3 Months Ended						6 Months Ended
		Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2018 USD ($) policy	Jun. 30, 2017 USD ($)
Related Party Transaction [Line Items]
Commissions and fees		$ 169,004,000				$ (116,167,000)		$ 298,159,000	$ 11,835,000
Other invested assets	[1]	313,920,000		$ 263,074,000				313,920,000
Net investment income		81,649,000				91,041,000		159,564,000	180,656,000
Fee income from revenue sharing agreement		3,544,000				4,390,000		7,017,000	8,577,000
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		500,000				500,000		700,000	700,000
Deferred compensation program expense		2,000,000				2,000,000		4,000,000	5,000,000
Pension plan expense		6,000,000				6,000,000		12,000,000	13,000,000
Welfare plan expense		7,000,000				7,000,000		$ 15,000,000	14,000,000
Defined contribution plan, employer matching contribution, percent (up to)								4.00%
Defined contribution plan, cost recognized		3,000,000				3,000,000		$ 5,000,000	5,000,000
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		3,783,000,000		3,688,000,000				$ 3,783,000,000
Fees related to Life Insurance, Corporate or Bank Owned, amount		11,000,000				11,000,000		23,000,000	23,000,000
Maximum amount of mortality risk		3,500,000						3,500,000
Prudential Financial
Related Party Transaction [Line Items]
Company's share of corporate expenses		19,000,000				15,000,000		$ 37,000,000	32,000,000
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		2,000,000		1,000,000				$ 2,000,000
Revenues related to long-term notes receivable		1,000,000				1,000,000		2,000,000	3,000,000
Line of credit facility, maximum borrowing capacity		2,200,000,000.0						2,200,000,000.0
Interest expense related to loans payable		300,000				400,000		400,000	600,000
Affiliated Entity | PAD
Related Party Transaction [Line Items]
Commissions and fees		189,000,000				160,000,000		363,000,000	315,000,000
Affiliated Entity | ASTISI and PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement		83,000,000				80,000,000		167,000,000	157,000,000
Affiliated Entity | PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement		3,000,000				4,000,000		5,000,000	7,000,000
Affiliated Entity | PGIM
Related Party Transaction [Line Items]
Net investment income		4,000,000				4,000,000		7,000,000	7,000,000
Prudential Financial Joint Ventures
Related Party Transaction [Line Items]
Other invested assets		92,000,000		$ 79,000,000				92,000,000
Net investment income		$ 2,000,000				$ 2,000,000		$ 2,000,000	$ 6,000,000

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