Details of Convertible Notes Reflected on Unaudited Condensed Consolidated Balance Sheet (Detail) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
2.50% Convertible Notes
Debt Instrument [Line Items]
Equity component carrying amount	$ 33,875
Unamortized discount	59,657
Net debt carrying amount	240,343
1.875% Convertible Notes
Debt Instrument [Line Items]
Equity component carrying amount	41,309	41,309
Unamortized discount	12,819	24,784
Net debt carrying amount	$ 274,681	$ 262,716

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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