Stock-Based Compensation Plans (Summary Of Stock Option Activity) (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Common Shares, Outstanding at beginning of the period	1,745,427		2,064,534
Common Shares, Granted	235,002		250,997
Common Shares, Exercised	(78,184)		(421,426)
Common Shares, Forfeited or canceled	(45,818)		(50,235)
Common Shares, Outstanding at end of the period	1,856,427		1,843,870
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted Average Strike Price, Outstanding at beginning of period	$ 42.31		$ 38.83
Weighted Average Strike Price, Granted	$ 37.97		$ 31.16
Weighted Average Strike Price, Exercised	$ 28.50		$ 20.27
Weighted Average Strike Price, Forfeited or canceled	$ 45.18		$ 36.42
Weighted Average Strike Price, Outstanding at end of period	$ 42.27		$ 42.09
Stock Options, Exercisable	1,845,560		1,840,731
Stock Options, Weighted Average Strike Price, Exercisable	$ 42.32		$ 42.11
Stock Options, Remaining Contractual Term, Outstanding, Years	2 years 4 months 24 days	[1]	3 years 2 months 12 days	[1]
Stock Options, Remaining Contractual Term, Exercisable, Years	2 years 4 months 24 days	[1]	3 years 2 months 12 days	[1]
Stock Options, Intrinsic Value, Outstanding	$ 6,786	[2]	$ 5,029	[2]
Stock Options, Intrinsic Value, Exercisable	$ 6,710	[2]	$ 5,010	[2]

[1] Represents the remaining weighted average contractual life in years.

[2]