Stock Options And Awards (Schedule Of Information For Stock Option Plans) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options	751,687	[1]
Weighted-average exercise price of outstanding options	$ 52.74
Number of securities remaining available for future issuance under equity compensation plan	871,698
Equity Compensation Plans Approved By Stockholders [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options	751,687	[1]
Weighted-average exercise price of outstanding options	$ 52.74
Number of securities remaining available for future issuance under equity compensation plan	871,698
Equity Compensation Plans Not Approved By Stockholders [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of outstanding options	Not applicable
2004 Plan [Member] | Unvested restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock, shares	132,784
2004 Plan [Member] | Unvested performance service awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock, shares	46,350

[1] Excludes 132,784 shares of unvested restricted stock awards and 46,350 of unvested performance units, which were granted pursuant to the 2004 Plan approved by the stockholders.