Leases - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) a	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) a	Sep. 30, 2018 USD ($)
Leases [Abstract]
Operating lease cost	$ 300,000		$ 700,000
Variable lease cost	$ 0		$ 0
Weighted average remaining lease term	6 years 3 months 11 days		6 years 3 months 11 days
Weighted average discount rate	5.38%		5.38%
Cash paid for amounts included in measurement of lease liabilities			$ 800,000
Right-of-use asset obtained in exchange for operating lease liability			500,000
Lease obligation incurred			$ 500,000
Land subject to ground leases | a	192		192
Below market lease, amortization 2019	$ 100,000		$ 100,000
Below market lease, amortization 2020	100,000		100,000
Below market lease, amortization 2021	100,000		100,000
Below market lease, amortization 2022	100,000		100,000
Below market Lease, amortization 2023	100,000		100,000
Lease income	$ 3,341,000	$ 3,341,000	$ 10,023,000	$ 10,034,000