XML 68 R54.htm IDEA: XBRL DOCUMENT v3.6.0.2
Retirement Plans, Summary of Funded Status at End of Year (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Pension Benefits [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 257,517 $ 243,588 $ 242,275
Benefit obligations (337,176) (297,325) (315,075)
Funded status and amount recognized at end of year (79,659) (53,737)  
SERP [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0 0
Benefit obligations (1,457) (1,526) (1,637)
Funded status and amount recognized at end of year (1,457) (1,526)  
Other Postretirement Benefits [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0 0
Benefit obligations (675) (891) $ (1,264)
Funded status and amount recognized at end of year $ (675) $ (891)