Income Taxes - Valuation allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Valuation allowance beginning of the year	$ 6.6	$ 4.2	$ 4.3
Increases (decreases) recorded as a expense (benefit) to income tax provision	0.5		(0.1)
Increases recorded as part of acquisition purchase accounting		2.4
Valuation allowance end of the year	$ 7.1	$ 6.6	$ 4.2