Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2016

BancShares Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

BancShares Plan

For the three months ended March 31, 2016 and 2015, the components of net periodic benefit cost are as follows:

	Three months ended March 31
(Dollars in thousands)	2016			2015
Service cost	$	3,220		$	3,600
Interest cost	7,180			6,748
Expected return on assets	(9,159		)	(8,295		)
Amortization of prior service cost	52			53
Amortization of net actuarial loss	1,600			2,833
Net periodic benefit cost	$	2,893		$	4,939

Bancorporation Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

Bancorporation Plan

For the three months ended March 31, 2016 and 2015, the components of net periodic benefit cost are as follows:

	Three months ended March 31
(Dollars in thousands)	2016			2015
Service cost	$	650		$	933
Interest cost	1,675			1,628
Expected return on assets	(2,779		)	(2,869		)
Net periodic benefit cost	$	(454	)	$	(308	)