Other Postretirement Benefit Plans (Schedule Of Net Periodic Postretirement Benefit Cost And Other Comprehensive Income) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 6,173	$ 6,746	$ 6,982
Net periodic pension cost	72	202	(5,406)
Current year actuarial (gain) loss	11,558	13,697
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	41	61	67
Actuarial loss amortization		7
Net periodic pension cost	41	68	67
Purchase price adjustment - CBI		36
Total postretirement benefit welfare cost	41	104	67
Current year actuarial (gain) loss	(169)	133	14
Actuarial loss amortization		(7)
Total recognized in other comprehensive income	(169)	126	14
Total recognized in net periodic postretirement income and other comprehensive income	$ (128)	$ 230	$ 81