Related Party Transactions (Narrative) (Details) - USD ($)	3 Months Ended						6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Investment expense	$ 6,785,000				$ 5,400,000		$ 13,178,000	$ 9,353,000
Commissions and fees	455,682,000				524,788,000		952,551,000	1,032,722,000
Other invested assets	529,040,000		$ 474,013,000				529,040,000		$ 474,013,000
Net investment income	158,426,000				131,972,000		281,463,000	257,041,000
Fee income from revenue sharing agreement	105,849,000				115,205,000		250,982,000	224,593,000
Accrued investment income	116,317,000		102,724,000				116,317,000		102,724,000
Contributed capital							0		0
Prudential Insurance
Related Party Transaction [Line Items]
Stock option program plan expense	0.0				100,000		100,000	100,000
Deferred compensation program expense	0.0				200,000		300,000	500,000
Pension plan expense	500,000				600,000		1,100,000	1,100,000
Welfare plan expense	400,000				500,000		$ 1,000,000.0	1,100,000
Defined contribution plan employer matching contribution percent							4.00%
Defined contribution plan, cost recognized	200,000				300,000		$ 500,000	500,000
Affiliated Entity
Related Party Transaction [Line Items]
Net investment income	300,000						300,000
Accrued interest receivable related to long-term notes receivables	100,000		0.0				100,000		0.0
Revenue related to long-term notes receivable	400,000				100,000		800,000	200,000
Accrued investment income	200,000						200,000
Interest expense related to loans payable	8,000,000				24,000,000		36,000,000	40,000,000
Affiliated Entity | PAD
Related Party Transaction [Line Items]
Commissions and fees	29,000,000				25,000,000		52,000,000	49,000,000
Affiliated Entity | ASTISI and PGIM Investments
Related Party Transaction [Line Items]
Fee income from revenue sharing agreement	21,000,000				24,000,000		43,000,000	48,000,000
Affiliated Entity | PGIM
Related Party Transaction [Line Items]
Investment expense	5,000,000				4,000,000		10,000,000	8,000,000
Prudential Financial Joint Venture
Related Party Transaction [Line Items]
Other invested assets	444,000,000		391,000,000				444,000,000		$ 391,000,000
Net investment income	15,000,000				4,000,000		3,000,000	9,000,000
Prudential Financial
Related Party Transaction [Line Items]
Company's share of corporate expenses (benefits)	2,000,000				4,000,000		6,000,000	$ 8,000,000
Line of credit facility, maximum borrowing capacity	9,000,000,000						$ 9,000,000,000
PAI
Related Party Transaction [Line Items]
Return of capital	$ 173,000,000	$ 207,000,000	$ 241,000,000	$ 245,000,000	$ 247,000,000	$ 245,000,000