Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Goodwill, impairment loss	$ 0.0	$ 7.6
Other Operations
Finite-Lived Intangible Assets [Line Items]
Impairments	0.4	0.4
Goodwill, impairment loss	7.6	7.6
Fresh Insurance Services Group Limited
Finite-Lived Intangible Assets [Line Items]
Impairments	6.2	2.4
NSM
Finite-Lived Intangible Assets [Line Items]
Goodwill, impairment loss	0.0	0.0
Total other intangible assets
Finite-Lived Intangible Assets [Line Items]
Impairments	$ 6.2	$ 2.8