Schedule II - Condensed Financial Information of Registrant (Parent Only) - Statements of Operations (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues
Net investment income (loss)		$ 3,830.4	$ 4,406.1	$ 3,890.6
Net realized capital gains (losses)	[1]	(258.4)	2.5	302.6
Total revenues		17,491.6	14,262.7	14,741.7
Expenses
Other operating costs and expenses		4,965.9	4,987.3	4,646.5
Total expenses		11,431.5	12,179.1	13,048.2
Loss before income taxes		6,060.1	2,083.6	1,693.5
Income taxes (benefits)		1,207.9	326.2	265.0
Net income (loss) attributable to Principal Financial Group, Inc.		4,811.6	1,710.6	1,395.8
Principal Financial Group, Inc. Parent Only | Legal Entities
Revenues
Net investment income (loss)		16.8	18.6	13.3
Net realized capital gains (losses)		(53.6)	(14.9)	7.0
Total revenues		(36.8)	3.7	20.3
Expenses
Other operating costs and expenses		188.8	160.9	200.0
Total expenses		188.8	160.9	200.0
Loss before income taxes		(225.6)	(157.2)	(179.7)
Income taxes (benefits)		(33.8)	(35.6)	(46.1)
Equity in the net income (loss) of subsidiaries		5,003.4	1,832.2	1,529.4
Net income (loss) attributable to Principal Financial Group, Inc.		$ 4,811.6	$ 1,710.6	$ 1,395.8

[1] Includes realized and unrealized gains (losses). See Note 4, Investments, for further details.