Fair Value Of Financial Instruments (Schedule Of Fair Values Of Financial Assets And Liabilities Measured On Recurring Basis) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance policies	$ 11.9		$ 10.6
Deferred compensation plan liabilities	3.3		2.2
Earn-out Arrangements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	143.6		80.5
Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction rate securities	14.4	[1]	13.6	[1]
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance policies	11.9		10.6
Deferred compensation plan liabilities	3.3		2.2
Level 1 [Member] | Earn-out Arrangements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	0		0
Level 1 [Member] | Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction rate securities	0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance policies	0		0
Deferred compensation plan liabilities	0		0
Level 2 [Member] | Earn-out Arrangements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	0		0
Level 2 [Member] | Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction rate securities	0		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance policies	0		0
Deferred compensation plan liabilities	0		0
Level 3 [Member] | Earn-out Arrangements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	143.6		80.5
Level 3 [Member] | Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction rate securities	$ 14.4		$ 13.6

[1] The Company’s auction rate securities maintain split ratings. For purposes of this table, securities are categorized according to their lowest rating.