Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2015

BancShares Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

BancShares Plan

For the three months ended March 31, 2015 and 2014, the components of net periodic benefit cost are as follows:

	Three months ended March 31
(Dollars in thousands)	2015			2014
Service cost	$	3,600		$	3,381
Interest cost	6,748			6,556
Expected return on assets	(8,295		)	(7,812		)
Amortization of prior service cost	53			53
Amortization of net actuarial loss	2,833			1,546
Net periodic benefit cost	$	4,939		$	3,724

Bancorporation Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

Bancorporation Plan

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

	Three months ended March 31
(Dollars in thousands)	2015
Service cost	$	933
Interest cost	1,628
Expected return on assets	(2,869		)
Amortization of prior service cost	—
Amortization of net actuarial loss	—
Net periodic benefit cost	$	(308	)