Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments (Details)

v3.8.0.1
Derivative Financial Instruments (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Mar. 31, 2016
derivative_instrument
Swap agreements as of December 31, 2017      
Derivative [Line Items]      
Number of instruments held | derivative_instrument     2
Fixed interest rate     0.89%
Derivatives, contract termination value $ 1,300    
Other assets | Swap agreements as of December 31, 2017      
Derivative [Line Items]      
Notional 75,000 $ 75,000  
Derivative Asset 1,329 $ 1,098  
Reclassification out of Accumulated Other Comprehensive Income      
Derivative [Line Items]      
Cash flow hedge gain (loss) to be reclassified within 12 months $ (700)