Income Tax Provision - Summary of Income Tax Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current income tax expense:
Current income tax expense on dispositions	$ 4,593,000
Deferred income tax expense:
Deferred income tax expense (benefit)	366,000
Total income tax expense	$ 4,959,000	$ 0	$ 0