XML 1016 R35.htm IDEA: XBRL DOCUMENT v3.20.1
Nature of Operations and Items Impacting Basis of Presentation - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Dividends $ 4.7 $ 6.0 $ 15.8
Dividends from retained earnings 1.3    
Dividends from additional paid in capital 3.4    
Assurant Employee Benefits | Disposal Group, Disposed of by Sale, Not Discontinued Operations      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Deferred gain on disposal $ 0.1