Annual report pursuant to Section 13 and 15(d)

Financial Instruments Financial Instruments - Additional Information (Details 4)

v3.10.0.1
Financial Instruments Financial Instruments - Additional Information (Details 4) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Derivative Asset $ 1,623,000 $ 734,000 $ 0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss) $ 889,000 734,000  
Fair Value, Liabilities, Transfers between Levels   $ 0