EMPLOYEE BENEFIT PLANS (Tables)
 9 Months Ended
Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]  
Employee Benefit Plan Amounts Recognized in the Consolidated Balance Sheets and Consolidated Statements of Income
The following table sets forth information concerning amounts recognized in First Financial’s Consolidated Statements of Income related to the Company's pension plan:
 
 
Three months ended
 
Nine months ended
 
 
September 30,
 
September 30,
(Dollars in thousands)
 
2016
 
2015
 
2016
 
2015
Service cost
 
$
1,308

 
$
1,175

 
$
3,925

 
$
3,525

Interest cost
 
581

 
550

 
1,743

 
1,650

Expected return on assets
 
(2,431
)
 
(2,375
)
 
(7,294
)
 
(7,125
)
Amortization of prior service cost
 
(103
)
 
(100
)
 
(310
)
 
(300
)
Net actuarial loss
 
420

 
450

 
1,261

 
1,350

     Net periodic benefit (income) cost
 
$
(225
)
 
$
(300
)
 
$
(675
)
 
$
(900
)