Quarterly report pursuant to Section 13 or 15(d)

Fair Value Disclosures - Financial Assets and Liabilities Measured at Fair Value (Details)

v3.7.0.1
Fair Value Disclosures - Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Supplemental Employee Retirement Plan [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
SERP $ 1,593 $ 1,407
Supplemental Employee Retirement Plan [Member] | Level 1    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
SERP 0 0
Supplemental Employee Retirement Plan [Member] | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
SERP 1,593 1,407
Supplemental Employee Retirement Plan [Member] | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
SERP 0 0
Interest Rate Swap [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps 6,857 7,611
Interest Rate Swap [Member] | Level 1    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps 0 0
Interest Rate Swap [Member] | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps 6,857 7,611
Interest Rate Swap [Member] | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps $ 0 $ 0