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				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Disclosure Earnings Per Share Computation Of Basic And Diluted Earnings Per Share [Abstract]
Income from continuing operations	$ 55,414		$ 42,838		$ 113,356		$ 93,811
Less: Non-controlling interest in subsidiaries' earnings	540		185		691		319
Income from continuing operations attributable to common shareholders	54,874		42,653		112,665		93,492
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0		19,909		0		20,732
Net income attributable to common shareholders	54,874		62,562		112,665		114,224
Average basic shares outstanding	57,908		57,762		57,684		57,787
Effect of dilutive stock options	920		852		910		917
Average diluted shares outstanding	58,828		58,614		58,594		58,704
Earnings per share - basic:
Income from continuing operations attributable to common shareholders	$ 0.95		$ 0.74		$ 1.95		$ 1.62
Discontinued operations, net of tax	$ 0.00		$ 0.34		$ 0.00		$ 0.36
Net income attributable to common shareholders	$ 0.95		$ 1.08		$ 1.95		$ 1.98
Earnings per share - diluted:
Income from continuing operations attributable to common shareholders	$ 0.93	[1]	$ 0.73	[1]	$ 1.92	[1]	$ 1.59	[1]
Discontinued operations, net of tax	$ 0.00	[1]	$ 0.34	[1]	$ 0.00	[1]	$ 0.35	[1]
Net income attributable to common shareholders	$ 0.93	[1]	$ 1.07	[1]	$ 1.92	[1]	$ 1.95	[1]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 55,414		$ 62,747		$ 113,356		$ 114,543

[1] EPS amounts may not add due to rounding