Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Earnings Per Share [Line Items]
Income from continuing operations	$ 57,942		$ 50,974
Less: Non-controlling interest in subsidiaries' earnings	151		134
Income from continuing operations attributable to common shareholders	57,791		50,840
Discontinued operations, net of tax	0		822
Net income attributable to common shareholders	$ 57,791		$ 51,662
Average basic shares outstanding	57,479		57,889
Effect of dilutive stock options	910		991
Average diluted shares outstanding	58,389		58,880
Earnings per share - basic:
Income from continuing operations attributable to common shareholders	$ 1.01		$ 0.88
Discontinued operations, net of tax	$ 0.00		$ 0.01
Net income attributable to common shareholders	$ 1.01		$ 0.89
Earnings per share - diluted:
Income from continuing operations attributable to common shareholders	$ 0.99	[1]	$ 0.86	[1]
Discontinued operations, net of tax	$ 0.00	[1]	$ 0.01	[1]
Net income attributable to common shareholders	$ 0.99	[1]	$ 0.88	[1]

[1] EPS amounts may not add due to rounding