Schedule II - Condensed Financial Information of Registrant (Parent Only) - Statements of Financial Position (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Assets
Fixed maturities, available-for-sale	$ 62,889.9	$ 78,154.5
Fixed maturities, trading	760.7	422.2
Other investments	6,075.9	5,478.3
Cash and cash equivalents	4,848.0	2,332.0
Deferred income taxes	115.5	85.0
Total assets	292,239.6	304,657.2
Liabilities
Long-term debt	3,997.0	4,280.2
Income taxes currently payable	19.2	15.5
Total liabilities	281,934.8	288,198.9
Stockholders' equity
Common stock, par value $0.01 per share; 2,500.0 million shares authorized; 489.8 million and 484.9 million shares issued as of 2022 and 2021; 243.5 million and 261.7 million shares outstanding as of 2022 and 2021	4.9	4.8
Additional paid-in capital	10,740.4	10,495.0
Retained earnings	17,042.3	12,884.5
Accumulated other comprehensive income (loss)	(7,199.0)	1,610.9
Treasury stock, at cost (246.3 million and 223.2 million shares as of 2022 and 2021)	(10,586.9)	(8,925.8)
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,001.7	16,069.4
Total liabilities and stockholders' equity	292,239.6	304,657.2
Principal Financial Group, Inc. Parent Only | Legal Entities
Assets
Fixed maturities, available-for-sale	17.1	1,051.9
Fixed maturities, trading		109.0
Other investments	12.0	10.4
Cash and cash equivalents	492.5	320.3
Income taxes receivable		20.4
Deferred income taxes	297.1	320.9
Amounts receivable from subsidiaries	5.4	5.5
Other assets	21.8	27.1
Investment in unconsolidated entities	13,448.7	18,932.4
Total assets	14,294.6	20,797.9
Liabilities
Long-term debt	3,929.2	4,226.2
Accrued investment payable	24.7	25.3
Income taxes currently payable	2.4
Pension liability	332.7	473.2
Other liabilities	3.9	3.8
Total liabilities	4,292.9	4,728.5
Stockholders' equity
Common stock, par value $0.01 per share; 2,500.0 million shares authorized; 489.8 million and 484.9 million shares issued as of 2022 and 2021; 243.5 million and 261.7 million shares outstanding as of 2022 and 2021	4.9	4.8
Additional paid-in capital	10,740.4	10,495.0
Retained earnings	17,042.3	12,884.5
Accumulated other comprehensive income (loss)	(7,199.0)	1,610.9
Treasury stock, at cost (246.3 million and 223.2 million shares as of 2022 and 2021)	(10,586.9)	(8,925.8)
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,001.7	16,069.4
Total liabilities and stockholders' equity	$ 14,294.6	$ 20,797.9