Leases (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lease renewal term	15 years	15 years
Notice required for termination of lease	6 months	6 months
Security deposit		$ 0.9
Letters of credit as security deposit	$ 5.5	$ 5.5
Minimum
Lessee, Lease, Description [Line Items]
Lease term	2 years	2 years
Sublease term	2 years	2 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term	10 years	10 years
Sublease term	3 years	3 years