Leases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Leases
Options to extend the leases			true
Options to terminate			true
Termination term			1 year
Operating lease cost	$ 1.3	$ 1.7	$ 4.7	$ 5.1
Minimum
Leases
Remaining lease terms	1 year		1 year
Maximum
Leases
Remaining lease terms	5 years		5 years
Renewal term	5 years		5 years