Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2013

Retirement Plans [Abstract]

Net Periodic Benefit Cost

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

	Pension Benefits					Pension Benefits
	For the three months ended				For the six months ended
	June 30,					June 30,
		2013		2012			2013	2012
($ in thousands)
Components of net periodic pension benefit cost
Service cost	$	12,834	$	10,492		$	25,668	$          20,984
Interest cost on projected benefit obligation		18,880		19,658			37,760	39,316
Expected return on plan assets		(24,590)		(24,089)			(49,180)	(48,177)
Amortization of prior service cost /(credit)		2		(50)			4	(100)
Amortization of unrecognized loss		10,072		7,787			20,144	15,573
Net periodic pension benefit cost	$	17,198	$	13,798		$	34,396	$          27,596
	Postretirement Benefits					Postretirement Benefits
	Other Than Pensions (OPEB)					Other Than Pensions (OPEB)
		For the three months ended				For the six months ended
	June 30,						June 30,
		2013		2012			2013	2012
($ in thousands)
Components of net periodic postretirement benefit cost
Service cost	$	3,179	$	2,555		$	6,358	$            5,110
Interest cost on projected benefit obligation		4,440		4,460			8,880	8,920
Expected return on plan assets		(43)		(55)			(86)	(110)
Amortization of prior service cost/(credit)		(1,525)		(2,503)			(3,050)	(5,006)
Amortization of unrecognized loss		2,228		1,911			4,456	3,822
Net periodic postretirement benefit cost	$	8,279	$	6,368		$	16,558	$          12,736