Condensed Consolidated Statements of Shareholders’ Equity - USD ($)		Total		Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interest	Previously Reported	Previously Reported Common Stock	Previously Reported Paid-in Capital	Previously Reported Retained Earnings	Previously Reported Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2020	[1]									65,400,000
Beginning balance at Dec. 31, 2020	[1]								$ 3,508,000,000	$ 6,500,000	$ 1,805,200,000	$ 2,046,100,000	$ (349,800,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss		$ (123,700,000)	[2]			$ (123,700,000)
Other Comprehensive Loss, Net of Taxes (Note 16)		(51,800,000)					$ (51,800,000)
Cash Dividends and Dividend Equivalents to Shareholders		$ (81,000,000.0)				(81,000,000.0)
Dividends paid to shareholders per share (in dollars per share)		$ 1.24
Repurchases of Common Stock (Note 17)		$ (161,700,000)		$ (200,000)	$ (57,800,000)	(103,700,000)
Repurchases of Common Stock (in shares)		(2,085,000)		(2,100,000)
Equity-based Compensation Cost (Note 21)		$ 37,000,000.0			37,000,000.0
Equity-based Awards, Net of Shares Exchanged (Note 11) (in shares)				300,000
Equity-based Awards, Net of Shares Exchanged (Note 21)		(2,500,000)		$ 100,000	900,000	(3,500,000)
Issuances of Common Stock (in shares)				100,000
Comprehensive Loss attributable to Kemper Corporation		(175,500,000)
Shares Issued Under Employee Stock Purchase Plan (Note 17)		5,400,000			5,400,000
Ending balance (in shares) at Dec. 31, 2021	[1]									63,700,000
Ending balance at Dec. 31, 2021	[1]								$ 3,129,700,000	$ 6,400,000	$ 1,790,700,000	$ 1,734,200,000	$ (401,600,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss		(286,600,000)	[2]			(286,600,000)
Other Comprehensive Loss, Net of Taxes (Note 16)		(113,300,000)					(113,300,000)
Cash Dividends and Dividend Equivalents to Shareholders		$ (80,400,000)				(80,400,000)
Dividends paid to shareholders per share (in dollars per share)		$ 1.24
Equity-based Compensation Cost (Note 21)		$ 17,700,000			17,700,000
Equity-based Awards, Net of Shares Exchanged (Note 11) (in shares)				100,000
Equity-based Awards, Net of Shares Exchanged (Note 21)		(1,400,000)		$ 0	(600,000)	(800,000)
Issuances of Common Stock (in shares)				100,000
Comprehensive Loss attributable to Kemper Corporation		(399,900,000)
Shares Issued Under Employee Stock Purchase Plan (Note 17)		4,900,000			4,900,000
Ending balance (in shares) at Dec. 31, 2022	[1]			63,900,000
Ending balance at Dec. 31, 2022	[1]	2,670,600,000		$ 6,400,000	1,812,700,000	1,366,400,000	(514,900,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss		(272,300,000)				(272,100,000)		$ (200,000)
Other Comprehensive Loss, Net of Taxes (Note 16)		154,100,000					154,100,000
Cash Dividends and Dividend Equivalents to Shareholders		$ (80,100,000)				(80,100,000)
Dividends paid to shareholders per share (in dollars per share)		$ 1.24
Equity-based Compensation Cost (Note 21)		$ 29,000,000.0			29,000,000.0
Equity-based Awards, Net of Shares Exchanged (Note 11) (in shares)				100,000
Equity-based Awards, Net of Shares Exchanged (Note 21)		(600,000)		$ 0	(700,000)	100,000
Issuances of Common Stock (in shares)				100,000
Comprehensive Loss attributable to Kemper Corporation		(118,000,000.0)
Shares Issued Under Employee Stock Purchase Plan (Note 17)		4,300,000			4,300,000
Ending balance (in shares) at Dec. 31, 2023				64,100,000
Ending balance at Dec. 31, 2023		$ 2,505,000,000		$ 6,400,000	$ 1,845,300,000	$ 1,014,300,000	$ (360,800,000)	$ (200,000)

[1] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been recast to reflect application of the new guidance. See Note 2 to the Consolidated Financial Statements for additional information.

[2] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been recast to reflect application of the new guidance. See Note 2 to the Consolidated Financial Statements for additional information.