Summary of Significant Accounting Policies (Accounts Receivable) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accounts Receivable
Accounts receivable, allowance for doubtful accounts	$ 1,241,000	$ 1,217,000
Prepaid Expenses and Other Current Assets
Prepaid insurance premiums	5,394,000	1,239,000
Insurance claim receivables	$ 2,156,000	$ 115,000