Leases - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Lease not yet commenced, undiscounted amount	$ 5.9
Minimum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term	40 years