Goodwill and Intangible Assets - Goodwill (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment	[1]	$ 224,800,000	$ 0	$ 224,800,000	$ 0
Goodwill		227,900,000	452,700,000	227,900,000	452,700,000		$ 452,700,000
Amortization of intangible assets		5,500,000	14,300,000	20,100,000	28,500,000
Goodwill, Impaired, Accumulated Impairment Loss		0		$ 0
Property
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment		$ 224,800,000
Personal Lines | Agency
Finite-Lived Intangible Assets [Line Items]
Goodwill Attributable to Reporting Unit, Percent		98.00%		98.00%
Policies in force
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 0	$ 256,200,000	$ 0	$ 256,200,000		$ 256,200,000
Policies in force | Fully Amortized
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount						$ 256,200,000

[1] See Note 12 – Goodwill and Intangible Assets for further discussion.