Commitments and Contingencies - Future Minimum Rental Payments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
2017 (remaining)	$ 825,000		$ 825,000
2018	1,754,000		1,754,000
2019	1,754,000		1,754,000
2020	1,754,000		1,754,000
2021	1,754,000		1,754,000
2022 and thereafter	34,872,000		34,872,000
Total	42,713,000		42,713,000
Other Expenses [Abstract]
Operating ground lease expense	$ 311,000	$ 237,000	$ 623,000	$ 493,000