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Stock Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Based Compensation
Stock Options Granted (in shares)	423,000.00	1,617,000.00	804,000.00
Vesting percentage on each anniversary of the grant date	25.00%
Maximum term for stock options	6 years 3 months	6 years 3 months
Stock based compensation expense	$ 6.2	$ 3.6
Grant date fair value of stock options granted	$ 10.63	$ 11.12
Unrecognized compensation cost related to unvested stock options	$ 12.3
Unrecognized compensation cost related to unvested options, recognized weighted-average period	2 years 7 months 6 days
Omnibus Plan
Stock Based Compensation
Share available for issuance	0
Class A common stock
Stock Based Compensation
Number of shares reserved	800,000
Class A common stock \| Omnibus Plan
Stock Based Compensation
Shares reserved for future issuance	3,914,000
Share available for issuance	2,017,000	413,000
Maximum
Stock Based Compensation
Maximum term for stock options	10 years