Goodwill And Other Intangible Assets (Rollforward of Intangible Assets, Including Goodwill) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Goodwill and Other Intangible Assets [Roll Forward]
Goodwill, beginning balance	$ 824,707,000		$ 714,800,000
Currency translation adjustments, goodwill	(700,000)
Goodwill, ending balance	824,014,000		714,800,000
Other intangible assets, non-amortizing, beginning balance	66,100,000		66,200,000
Currency translation adjustments, non-amortizing intangible assets	(100,000)
Other intangible assets, non-amortizing, ending balance	66,000,000		66,200,000
Other intangible assets, amortizing, beginning balance	71,000,000	[1]	44,500,000
Amortization expense	(4,200,000)		(2,800,000)
Currency translation adjustments, amortizing intangible assets	0
Other intangible assets, amortizing, ending balance	66,800,000	[1]	41,700,000
Goodwill and other intangible assets, beginning balance	961,807,000		825,500,000
Currency translation adjustments, goodwill and other intangible assets	(800,000)
Goodwill and other intangible assets, ending balance	956,899,000		822,700,000
Earn-out Arrangements [Member]
Goodwill and Other Intangible Assets [Roll Forward]
Accruals of acquisition-related contingent consideration	$ 0	[2]	$ 0	[2]

[1] Consists principally of customer relationships, backlog, trade names and non-compete agreements with finite lives.

[2] Represents contingent consideration for acquisitions prior to January 1, 2009, which is only accrued as earned, in accordance with U.S. GAAP.