Employee Benefits
 9 Months Ended
Sep. 30, 2016
General Discussion of Pension and Other Postretirement Benefits [Abstract]  
Employee Benefits
Employee Benefits
Retirement Plans
The net periodic benefit cost recognized for the three, nine and twelve months ended September 30, 2016 and 2015 is made up of the components listed below as determined using the projected unit credit actuarial cost method (in thousands):
 
Three Months Ended
 
Nine Months Ended
 
Twelve Months Ended
 
September 30,
 
September 30,
 
September 30,
 
2016
 
2015
 
2016
 
2015
 
2016
 
2015
Components of net periodic benefit cost:
 
 
 
 
 
 
 
 
 
 
 
Service cost
$
2,191

 
$
2,394

 
$
6,001

 
$
6,594

 
$
8,199

 
$
8,707

Interest cost
3,250

 
3,622

 
9,780

 
10,872

 
13,403

 
14,563

Expected return on plan assets
(4,734
)
 
(4,951
)
 
(14,159
)
 
(14,846
)
 
(19,108
)
 
(19,528
)
Amortization of:
 
 
 
 
 
 
 
 
 
 
 
Net loss
1,730

 
2,485

 
5,505

 
7,985

 
8,167

 
10,267

Prior service benefit
(875
)
 
(855
)
 
(2,630
)
 
(2,630
)
 
(3,506
)
 
(3,506
)
Net periodic benefit cost
$
1,562

 
$
2,695

 
$
4,497

 
$
7,975

 
$
7,155

 
$
10,503


During the nine months ended September 30, 2016, the Company contributed $8.8 million of its projected $9.4 million 2016 annual contribution to its retirement plans.
Other Postretirement Benefits
The net periodic benefit cost recognized for the three, nine and twelve months ended September 30, 2016 and 2015 is made up of the components listed below (in thousands): 
 
Three Months Ended
 
Nine Months Ended
 
Twelve Months Ended
 
September 30,
 
September 30,
 
September 30,
 
2016
 
2015
 
2016
 
2015
 
2016
 
2015
Components of net periodic benefit cost:
 
 
 
 
 
 
 
 
 
 
 
Service cost
$
749

 
$
841

 
$
2,179

 
$
2,591

 
$
3,042

 
$
3,302

Interest cost
871

 
976

 
2,616

 
3,026

 
3,625

 
4,142

Expected return on plan assets
(452
)
 
(503
)
 
(1,372
)
 
(1,553
)
 
(1,889
)
 
(2,082
)
Amortization of:
 
 
 
 
 
 
 
 
 
 
 
Prior service benefit
(788
)
 
(751
)
 
(2,363
)
 
(2,301
)
 
(3,130
)
 
(3,490
)
Net gain
(643
)
 
(519
)
 
(1,973
)
 
(1,519
)
 
(2,479
)
 
(2,186
)
Net periodic benefit cost (benefit)
$
(263
)
 
$
44

 
$
(913
)
 
$
244

 
$
(831
)
 
$
(314
)

During the nine months ended September 30, 2016, the Company contributed $1.6 million of its projected $1.7 million 2016 annual contribution to its other post retirement benefits plan.
During October 2016, the Company approved and communicated a plan amendment that is expected to result in a remeasurement. Effective January 1, 2017, retirees and dependents that are less than 65 years of age will be offered a choice between a $1,000 and $2,250 deductible plan. Additionally, retirees and dependents that are 65 years of age or greater will be covered by a fully insured Medicare advantage plan. The postretirement benefit obligation is estimated to decrease by approximately $32.7 million as a result of the October 1, 2016 remeasurement. The effects of the remeasurement will be recorded in the fourth quarter of 2016.