Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Measurement Hierarchy (Details)

v3.8.0.1
Fair Value Measurements - Measurement Hierarchy (Details) - USD ($)
Dec. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swaps (prepaids and other assets) $ 5,533,000 $ 3,993,000
Total assets 5,533,000 3,993,000
Interest rate swaps (other liabilities) 188,000  
Total liabilities 188,000  
Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swaps (prepaids and other assets) 0 0
Total assets 0 0
Interest rate swaps (other liabilities) 0  
Total liabilities 0  
Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swaps (prepaids and other assets) 5,533,000 3,993,000
Total assets 5,533,000 3,993,000
Interest rate swaps (other liabilities) 188,000  
Total liabilities 188,000  
Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swaps (prepaids and other assets) 0 0
Total assets 0 $ 0
Interest rate swaps (other liabilities) 0  
Total liabilities $ 0