Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2019 USD ($)	Sep. 30, 2019 renewal_option
Lessee, Lease, Description [Line Items]
Number of renewals (or more than) | renewal_option		1
Term of lease not commenced		20 years
Minimum
Lessee, Lease, Description [Line Items]
Renewal term		5 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term		20 years
Renewal term		10 years
Legacy-Starwood Office Building
Lessee, Lease, Description [Line Items]
Impairment loss from leased asset | $	$ 34