Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2012

Retirement Plans [Abstract]

Net period benefit cost for the pension and postretirement plans

		2012		2011	2011
Components of Net Periodic Benefit Cost	($ in Thousands)
Pension Plan:
Service cost	$	2,613	$	2,613	$	9,898
Interest cost		1,613		1,589		6,414
Expected return on plan assets		(3,558)		(3,220)		(12,896)
Amortization of prior service cost		17		18		72
Amortization of actuarial loss		640		451		2,024
Total net periodic benefit cost	$	1,325	$	1,451	$	5,512
Postretirement Plan:
Interest cost	$	47	$	50	$	198
Amortization of prior service cost		43		99		395
Total net periodic benefit cost	$	90	$	149	$	593