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				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Earnings Per Share [Line Items]
Income from continuing operations	$ 56,406		$ 51,219		$ 150,217		$ 148,498
Less: Non-controlling interest in subsidiaries' earnings	182		(134)		501		(123)
Income from continuing operations attributable to common shareholders	56,224		51,353		149,716		148,621
Discontinued operations, net of tax	901		1,187		21,633		2,823
Net income attributable to common shareholders	$ 57,125		$ 52,540		$ 171,349		$ 151,444
Average basic shares outstanding	57,123		58,048		57,565		58,202
Effect of dilutive stock options	750		1,010		870		1,128
Average diluted shares outstanding	57,873		59,058		58,435		59,330
Earnings per share - basic:
Income from continuing operations attributable to common shareholders	$ 0.99	[1]	$ 0.88	[1]	$ 2.61	[1]	$ 2.55	[1]
Discontinued operations, net of tax	$ 0.02	[1]	$ 0.02	[1]	$ 0.38	[1]	$ 0.05	[1]
Net income attributable to common shareholders	$ 1.00		$ 0.91		$ 2.98		$ 2.60
Earnings per share - diluted:
Income from continuing operations attributable to common shareholders	$ 0.97	[1]	$ 0.87	[1]	$ 2.56	[1]	$ 2.50	[1]
Discontinued operations, net of tax	$ 0.02	[1]	$ 0.02	[1]	$ 0.37	[1]	$ 0.05	[1]
Net income attributable to common shareholders	$ 0.99		$ 0.89		$ 2.93		$ 2.55

[1] EPS amounts may not add due to rounding