Goodwill and Other Intangible Assets - Fair Value of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 28, 2019	Apr. 04, 2019	Apr. 01, 2019	Mar. 12, 2019	Dec. 03, 2018	May 18, 2018	May 11, 2018
NSM
Goodwill [Line Items]
Goodwill and intangible assets acquired								$ 383.0
Fresh Insurance
Goodwill [Line Items]
Goodwill and intangible assets acquired							$ 54.6
KBK
Goodwill [Line Items]
Goodwill and intangible assets acquired						$ 59.4
Other Operations
Goodwill [Line Items]
Goodwill and intangible assets acquired					$ 13.1
Embrace Pet Insurance
Goodwill [Line Items]
Goodwill and intangible assets acquired				$ 70.6
Kudu
Goodwill [Line Items]
Goodwill and intangible assets acquired			$ 9.8
Renewal Rights
Goodwill [Line Items]
Goodwill and intangible assets acquired		$ 82.5
NSM
Goodwill [Line Items]
Goodwill and intangible assets acquired	$ 650.1