Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2014
Investment
Assets contributed to 401(k) Plan				$ 7.9
Restricted investments	$ 2.4	$ 3.4
401(k) Plan distribution period (in years)	2 years
Compensation expense for assets allocated to participants	$ 1.1	1.1	$ 1.2
Maximum
Investment
Realized gain (loss)	$ (0.1)	$ (0.1)	$ 0.1