Net Income Per Share (Summary Of Table Reconciling Basic And Diluted Net Income Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Basic Earnings Per Share, Net income	$ 27,206		$ 17,016		$ 48,929		$ 33,449
Basic Earnings Per Share, Weighted average common shares outstanding	94,514,000		94,479,000		94,479,000		94,456,000
Basic Earnings Per Share	$ 0.29		$ 0.18		$ 0.52		$ 0.35
Diluted Earnings Per Share, Net income	$ 27,206		$ 17,016		$ 48,929		$ 33,449
Diluted Earnings Per Share, Weighted average common shares outstanding	94,514,000		94,479,000
Diluted Earnings Per Share, Weighted average common shares outstanding	94,871,000		94,701,000		94,847,000		94,674,000
Diluted Earnings Per Share	$ 0.29		$ 0.18		$ 0.52		$ 0.35
Antidilutive securities were not included in the computation of net income per diluted share	3,113		4,606
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities: Restricted stock	339,000	[1]	203,000	[1]	350,000	[1]	194,000	[1]
Antidilutive securities were not included in the computation of net income per diluted share	0				1
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities: Stock options	18,000	[2]	19,000	[2]	18,000	[2]	24,000	[2]
Diluted Earnings Per Share, Weighted average common shares outstanding	94,871,000		94,701,000
Antidilutive securities were not included in the computation of net income per diluted share					3,106		4,606
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities were not included in the computation of net income per diluted share			1				87

[1] 0 and 1 shares of restricted stock and restricted stock units were not included in the computation of net income per diluted share for the second quarter ended June 30, 2012 and 2011, respectively, because the effect would be antidilutive. 1 and 87 shares of restricted stock and restricted stock units were not included in the computation of net income per diluted share for the six months ended June 30, 2012 and 2011, respectively, because the effect would be antidilutive.

[2] Options to purchase 3,113 shares and 4,606 shares outstanding at June 30, 2012 and 2011, respectively, were not included in the computation of net income per diluted share for the second quarter ended June 30, 2012 and 2011, respectively, because the exercise price of these options was greater than the average market price of the common shares and, therefore, the effect would be antidilutive. Options to purchase 3,106 and 4,606 shares outstanding at June 30, 2012 and 2011, respectively, were not included in the computation of net income per diluted share for the six months ended June 30, 2012 and 2011, respectively, because the exercise price of these options was greater than the average market price of the common shares and, therefore, the effect would be antidilutive.