Employee Benefit Plan (Tables)
 6 Months Ended
Jun. 30, 2017
Compensation and Retirement Disclosure [Abstract]  
Schedule of net periodic benefit cost and other comprehensive income
Components of Net periodic Benefit Cost

 
Pension Benefits
Three Months Ended
 
Life and Health
Three Months Ended
 
SERP Benefits
Three Months Ended
(in thousands)
6/30/2017

 
6/30/2016

 
6/30/2017

 
6/30/2016

 
6/30/2017

 
6/30/2016

Service cost
$
0

 
$
0

 
$
28

 
$
47

 
$
29

 
$
14

Interest cost
643

 
587

 
62

 
65

 
217

 
205

Expected return on plan assets
(1,256
)
 
(1,207
)
 
0

 
0

 
0

 
0

Amortization of net retirement plan actuarial loss
286

 
249

 
13

 
2

 
98

 
75

Amortization of net retirement plan prior service (credit) cost
(3
)
 
(4
)
 
(35
)
 
4

 
22

 
8

Net periodic benefit (income) cost
$
(330
)
 
$
(375
)
 
$
68

 
$
118

 
$
366

 
$
302


  
Components of Net periodic Benefit Cost

 
Pension Benefits
Six Months Ended
 
Life and Health
Six Months Ended
 
SERP Benefits
Six Months Ended
(in thousands)
6/30/2017

 
6/30/2016

 
6/30/2017

 
6/30/2016

 
6/30/2017

 
6/30/2016

Service cost
$
0

 
$
0

 
$
96

 
$
129

 
$
83

 
$
86

Interest cost
1,250

 
1,237

 
134

 
141

 
426

 
416

Expected return on plan assets
(2,523
)
 
(2,422
)
 
0

 
0

 
0

 
0

Amortization of net retirement plan actuarial loss
537

 
487

 
17

 
3

 
199

 
179

Amortization of net retirement plan prior service cost (credit)
(5
)
 
(7
)
 
(31
)
 
8

 
44

 
38

Net periodic benefit (income) cost
$
(741
)
 
$
(705
)
 
$
216

 
$
281

 
$
752

 
$
719