Significant Accounting Policies (Schedule Of Earnings Per Share) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Schedule Of Common Stock [Line Items]
Number of common shares outstanding at end of period-basic	40,431,518	40,060,000	40,431,518	40,060,000	40,175,426
Effect of using weighted average common shares outstanding	(9,000)	(1,000)	(140,000)	(5,000)
Weighted average basic common shares outstanding-basic	40,423,000	40,059,000	40,292,000	40,055,000
Dilutive effect of common stock options	166,000	237,000	200,000	256,000
Weighted average diluted common shares outstanding-diluted	40,589,000	40,296,000	40,492,000	40,311,000