Earnings Per Share (Schedule Of Reconciliation Of Basic Earnings Per Share To Diluted Earnings Per Share) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 6,668		$ 6,241		$ 21,329		$ 18,380
Net income attributable to participating securities	(20)		(44)		(85)		(147)
Net income available to common shareholders	$ 6,648	[1]	$ 6,197	[1]	$ 21,244	[1]	$ 18,233	[1]
Weighted average common shares outstanding	104,028		102,422		103,720		102,172
Effect of dilutive securities	1,648		1,864		1,753		1,876
Weighted average common shares and dilutive securities outstanding	105,676		104,286		105,473		104,048
Earnings per share - basic	$ 0.06		$ 0.06		$ 0.20		$ 0.18
Earnings per share - diluted	$ 0.06		$ 0.06		$ 0.20		$ 0.18

[1] Basic weighted average common shares outstanding 104,028 102,422 103,720 102,172 Basic weighted average common shares outstanding and participating securities 104,324 103,170 104,085 103,029 Percentage allocated to common stockholders 99.7 % 99.3 % 99.6 % 99.2 %