Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2013

Retirement Plans [Abstract]

Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost:

	Pension Benefits
		For the three months ended
		March 31,
		2013			2012
($ in thousands)
Components of net periodic pension benefit cost
Service cost		$	12,834		$	10,492
Interest cost on projected benefit obligation			18,880			19,658
Expected return on plan assets			(24,590	)		(24,088	)
Amortization of prior service cost /(credit)			2			(50	)
Amortization of unrecognized loss			10,072			7,786
Net periodic pension benefit cost		$	17,198		$	13,798
	Postretirement Benefits
	Other Than Pensions (OPEB)
		For the three months ended
		March 31,
			2013			2012
($ in thousands)
Components of net periodic postretirement benefit cost
Service cost		$	3,179		$	2,555
Interest cost on projected benefit obligation			4,440			4,460
Expected return on plan assets			(43	)		(55	)
Amortization of prior service cost/(credit)			(1,525	)		(2,503	)
Amortization of unrecognized loss			2,228			1,911
Net periodic postretirement benefit cost		$	8,279		$	6,368