Defined Benefit Pension Plans (Tables)

9 Months Ended

Sep. 30, 2015

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Components of Net Periodic Benefit Cost

The composition of net periodic benefit cost was as follows:

(Dollars in thousands)	Qualified Pension Plan												Non-Qualified Retirement Plans
	Three months						Nine months						Three months				Nine months
Periods ended September 30,	2015			2014			2015			2014			2015		2014		2015		2014
Net Periodic Benefit Cost:
Service cost		$615			$538			$1,844			$1,614			$20		$11		$59		$34
Interest cost	731			723			2,195			2,168			122		119		367		358
Expected return on plan assets	(1,129		)	(1,016		)	(3,386		)	(3,047		)	—		—		—		—
Amortization of prior service (credit) cost	(6		)	(6		)	(17		)	(17		)	—		—		—		—
Recognized net actuarial loss	313			115			937			345			61		18		183		53
Net periodic benefit cost		$524			$354			$1,573			$1,063			$203		$148		$609		$445