Fair Value of Financial Instruments (Details 2) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of derivative liabilities at beginning of period	$ 1,232,000
Net realized and unrealized losses (gains) included in income	(677,000)
Purchases, Sales, Issues and Settlements, Net	343,000
Fair value of derivative liabilities at end of period	898,000
Changes in net unrealized losses (gains) included in income on instruments held at end of period	$ (677,000)
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value		$ 1,724,533,000	$ 1,615,102,000
Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value		$ 0	$ 0