Pension And Other Postretirement Benefit Plans (Schedule Of Changes In Level 3 Investments Measured At Fair Value) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 3,269,000	$ 4,173,000
Relating to assets still held at the reporting date	587,000	(527,000)
Relating to assets sold during the period	(1,776,000)	(377,000)
Fair value of plan assets at end of year	2,080,000	3,269,000
Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	1,012,000	1,089,000
Relating to assets still held at the reporting date	298,000	14,000
Relating to assets sold during the period	(278,000)	(91,000)
Fair value of plan assets at end of year	1,032,000	1,012,000
Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	2,242,000	2,407,000
Relating to assets still held at the reporting date	289,000	121,000
Relating to assets sold during the period	(1,483,000)	(286,000)
Fair value of plan assets at end of year	1,048,000	2,242,000
Other Receivables (Payables), net [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	15,000	677,000
Relating to assets still held at the reporting date		(662,000)
Relating to assets sold during the period	(15,000)
Fair value of plan assets at end of year		$ 15,000