Acquisitions (Fair Value, Valuation Techniques and Related Unobservable Inputs of Level 3) (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	20.2
Customer relationships [Member] | Income Approach Valuation Technique [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Valuation Technique	Excess earnings, with and without method
Customer relationships [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	16.00%
Attrition rate	7.00%
Customer relationships [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	17.50%
Attrition rate	20.00%
Technology Equipment [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	13.4
Technology Equipment [Member] | Income Approach Valuation Technique [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Valuation Technique	Excess earnings, relief- from-royalty method, cost approach
Technology Equipment [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	16.00%
Obsolescence factor	10.00%
Royalty rate (after-tax)	4.50%
Technology Equipment [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	17.00%
Obsolescence factor	20.00%
Tradename [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	3.1
Tradename [Member] | Income Approach Valuation Technique [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Valuation Technique	Relief-from-royalty method
Tradename [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	15.50%
Royalty rate (after-tax)	0.50%
Tradename [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Discount rate	17.50%
Royalty rate (after-tax)	1.20%
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	0.9
Discount rate	17.50%
Noncompete Agreements [Member] | Income Approach Valuation Technique [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Valuation Technique	With and without method
Contingent Consideration [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	3.5
Discount rate	4.50%
Contingent Consideration [Member] | Income Approach Valuation Technique [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Valuation Technique	Probability weighted discounted future cash flows