Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

Acquisitions (Provisional Amount Of Goodwill Recognized) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Business Acquisition [Line Items]
Goodwill on acquisition	$ 670,294	$ 1,452,986	$ 1,484,072
Whitehall Group [Member]
Business Acquisition [Line Items]
Fair value of previously held interest	250,156
Consideration paid for the remaining shares in Whitehall	75,713
Less: Net identifiable assets and liabilities	(55,238)
Goodwill on acquisition	$ 270,631