Schedule Of Financial Assets And Liabilities Subject To Fair Value Measurement Provisions (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	$ 40,996	$ 19,985
Total liabilities at fair value	(469)	(1,801)
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	38,591	15,275
Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		3,555
Stock
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	186	170
Derivative Instruments - Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		985
Derivative Instruments - Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities at fair value	(469)	(1,801)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	38,777	15,445
Total liabilities at fair value	0	0
Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	38,591	15,275
Level 1 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		0
Level 1 | Stock
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	186	170
Level 1 | Derivative Instruments - Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 1 | Derivative Instruments - Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities at fair value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	2,219	4,540
Total liabilities at fair value	(469)	(1,801)
Level 2 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 2 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		3,555
Level 2 | Stock
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 2 | Derivative Instruments - Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	2,219	985
Level 2 | Derivative Instruments - Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities at fair value	(469)	(1,801)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		0
Total liabilities at fair value	0	0
Level 3 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 3 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value		0
Level 3 | Stock
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 3 | Derivative Instruments - Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets at fair value	0	0
Level 3 | Derivative Instruments - Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities at fair value	$ 0	$ 0