Annual report pursuant to Section 13 and 15(d)

Derivatives - Narrative (Details)

v3.8.0.1
Derivatives - Narrative (Details)
Dec. 31, 2017
USD ($)
interest_rate_swap
Dec. 31, 2016
USD ($)
interest_rate_swap
Derivative [Line Items]    
Derivative liability   $ 16,948,000
Derivative amount not offset against collateral $ 0 0
Recurring    
Derivative [Line Items]    
Derivative asset 7,058,000 8,521,000
Derivative liability 13,817,000 16,948,000
Level 2 | Recurring    
Derivative [Line Items]    
Derivative asset $ 7,058,000 $ 8,521,000
Number of instruments held | interest_rate_swap 6 7
Derivative liability $ 13,817,000 $ 16,948,000
Interest Rate Swap | Cash flow hedge    
Derivative [Line Items]    
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net $ 4,672,000  
Interest Rate Swap | Level 2 | Recurring    
Derivative [Line Items]    
Number of derivative instruments held | interest_rate_swap 2 1
Derivative asset $ 7,058,000 $ 8,521,000
Derivative liability $ 13,817,000