Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2019

BancShares Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

BancShares Plan

For the three and nine months ended September 30, 2019 and 2018, the components of net periodic benefit cost are as follows:

	Three months ended September 30						Nine months ended September 30
(Dollars in thousands)	2019			2018			2019			2018
Service cost	$	2,628		$	3,396		$	7,886		$	10,187
Interest cost	7,557			7,093			22,669			21,281
Expected return on assets	(12,876		)	(11,966		)	(38,629		)	(35,899		)
Amortization of prior service cost	15			19			43			59
Amortization of net actuarial loss	2,099			3,398			6,297			10,192
Net periodic (benefit) cost	$	(577	)	$	1,940		$	(1,734	)	$	5,820

Bancorporation Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

Bancorporation Plan

For the three and nine months ended September 30, 2019 and 2018, the components of net periodic benefit cost are as follows:

	Three months ended September 30						Nine months ended September 30
(Dollars in thousands)	2019			2018			2019			2018
Service cost	$	563		$	643		$	1,689		$	1,929
Interest cost	1,759			1,588			5,276			4,767
Expected return on assets	(2,771		)	(3,106		)	(8,314		)	(9,322		)
Amortization of net actuarial loss	631			78			1,895			235
Net periodic cost (benefit)	$	182		$	(797	)	$	546		$	(2,391	)