Changes In Equity And Comprehensive Income (Summary Of Changes In Equity) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period			$ 1,150.8	$ 1,070.6
Dividends			(57.8)	(57.4)
Reacquisition on open market			0.0	(25.0)
Exercise of stock options, net of shares reacquired			9.6	7.3
Stock compensation expense			16.8	15.7
Excess tax benefit from stock based compensation			0.1	(0.2)
Net income	$ 63.7	$ 57.2	187.3	164.4
Other comprehensive income (loss)	(3.4)	(24.6)	17.2	(64.9)
Comprehensive income	60.3	32.6	204.5	99.5
Balance, end of period	1,324.0	1,110.4	1,324.0	1,110.4
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period			1,139.4	1,059.8
Dividends			(57.8)	(57.4)
Reacquisition on open market			0.0	(25.0)
Exercise of stock options, net of shares reacquired			9.6	7.3
Stock compensation expense			16.8	15.7
Excess tax benefit from stock based compensation			0.1	(0.2)
Net income			186.8	163.7
Other comprehensive income (loss)			17.2	(64.5)
Comprehensive income			204.0	99.2
Balance, end of period	1,312.1	1,099.3	1,312.1	1,099.3
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period			11.4	10.8
Net income			0.5	0.7
Other comprehensive income (loss)			0.0	(0.4)
Comprehensive income				0.3
Balance, end of period	$ 11.9	$ 11.1	$ 11.9	$ 11.1