Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Other Related Party Transactions (Details) - USD ($)	12 Months Ended
Other Related Party Transactions (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Minority interest in partnership
Related Party Transaction [Line Items]
Operating costs under lease	$ 2,100,000	$ 2,600,000	$ 2,400,000
Independent Directors \| Consulting Agreement
Related Party Transaction [Line Items]
Investment and other business consulting services fees			37,500
Chief Executive Officer
Related Party Transaction [Line Items]
Total fees paid for the use of plane	$ 0	$ 123,000	$ 314,000