Balances in the Allowance Accounts (Detail) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Current	$ 61,804,000	$ 57,385,000
Non-current (included in other assets, net)	2,850,000	3,150,000
Allowance for Doubtful Accounts Receivable, Total	$ 64,654,000	$ 60,535,000