Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2014

Retirement Plans [Abstract]

Net Periodic Benefit Cost

	Pension Benefits
	For the three months ended
	March 31,
	2014		2013
($ in thousands)
Components of net periodic pension benefit cost
Service cost	$	9,940	$	12,834
Interest cost on projected benefit obligation		19,824		18,880
Expected return on plan assets		(23,512)		(24,590)
Amortization of prior service cost /(credit)		11		2
Amortization of unrecognized loss		4,819		10,072
Net periodic pension benefit cost	$	11,082	$	17,198

	Postretirement Benefits
	Other Than Pensions (OPEB)
	For the three months ended
	March 31,
	2014		2013
($ in thousands)
Components of net periodic postretirement benefit cost
Service cost	$	2,553	$	3,179
Interest cost on projected benefit obligation		4,788		4,440
Expected return on plan assets		(7)		(43)
Amortization of prior service cost/(credit)		(890)		(1,525)
Amortization of unrecognized loss		722		2,228
Net periodic postretirement benefit cost	$	7,166	$	8,279