Leases - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	9 years 10 months 20 days
Termination period	1 year
Operating lease not yet commenced	$ 1
Minimum
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	31 years 1 month 6 days
Extension period	10 years