Stock-Based Compensation Plans (Summary Of Stock Option Activity) (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, at beginning of period, Number of Shares	2,820,285	2,513,327
Options granted, Number of Shares	0	398,616
Options exercised, Number of Shares	29,833	62,707
Options forfeited or expired, Number of Shares	45,301	104,085
Options outstanding, at end of period, Number of Shares	2,745,151	2,745,151
Options exercisable, at end of period, Number of Shares	2,168,744	2,168,744
Options expected to vest, at end of period, Number of Shares	530,693	530,693
Options outstanding, at beginning of period, Weighted-Average Exercise Price (in dolars per share)	$ 29.27	$ 30.03
Options granted, Weighted-Average Exercise Price (in dolars per share)	$ 0	$ 23.81
Options exercised, Weighted-Average Exercise Price (in dolars per share)	$ 12.85	$ 12.85
Options forfeited or expired, Weighted-Average Exercise Price (in dolars per share)	$ 27.52	$ 31.32
Options outstanding, at end of period, Weighted-Average Exercise Price (in dolars per share)	$ 29.47	$ 29.47
Options exercisable, at end of period, Weighted-Average Exercise Price (in dolars per share)	$ 31.86	$ 31.86
Options expected to vest, at end of period, Weighted-Average Exercise Price (in dolars per share)	$ 20.25	$ 20.25