Fair Value of Financial Instruments (Details) (Recurring [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financial Assets
Prepaid expense and other current assets - forward foreign exchange contracts	$ 269
Total financial assets	78,183	71,589
Accrued and other current liabilities - Forward foreign exchange contracts	350	631
Financial Liability
Accrued and other current liabilities - Forward foreign exchange contracts	350	631
Commercial paper [Member]
Financial Assets
Total financial assets	9,520
Level I [Member]
Financial Assets
Total financial assets	5,936	51,589
Level II [Member]
Financial Assets
Prepaid expense and other current assets - forward foreign exchange contracts	269
Total financial assets	72,247	20,000
Accrued and other current liabilities - Forward foreign exchange contracts	350	631
Financial Liability
Accrued and other current liabilities - Forward foreign exchange contracts	350	631
Level II [Member] | Commercial paper [Member]
Financial Assets
Total financial assets	9,520
Level III [Member]
Financial Assets
Prepaid expense and other current assets - forward foreign exchange contracts
Total financial assets
Accrued and other current liabilities - Forward foreign exchange contracts
Financial Liability
Accrued and other current liabilities - Forward foreign exchange contracts
Level III [Member] | Commercial paper [Member]
Financial Assets
Total financial assets
Cash equivalents [Member] | Bank deposits [Member]
Financial Assets
Total financial assets	12,519	20,000
Cash equivalents [Member] | Commercial paper [Member]
Financial Assets
Total financial assets	16,997
Cash equivalents [Member] | Money market funds [Member]
Financial Assets
Total financial assets	3,186	50,002
Cash equivalents [Member] | Level I [Member] | Money market funds [Member]
Financial Assets
Total financial assets	3,186	50,002
Cash equivalents [Member] | Level II [Member] | Bank deposits [Member]
Financial Assets
Total financial assets	12,519	20,000
Cash equivalents [Member] | Level II [Member] | Commercial paper [Member]
Financial Assets
Total financial assets	16,997
Cash equivalents [Member] | Level III [Member] | Bank deposits [Member]
Financial Assets
Total financial assets
Cash equivalents [Member] | Level III [Member] | Commercial paper [Member]
Financial Assets
Total financial assets
Cash equivalents [Member] | Level III [Member] | Money market funds [Member]
Financial Assets
Total financial assets
Short-term investments [Member] | Mutual funds [Member]
Financial Assets
Total financial assets	2,750	1,587
Short-term investments [Member] | US agency securities [Member]
Financial Assets
Total financial assets	2,002
Short-term investments [Member] | Corporate debt obligations [Member]
Financial Assets
Total financial assets	20,877
Short-term investments [Member] | Bank deposits [Member]
Financial Assets
Total financial assets	10,063
Short-term investments [Member] | Level I [Member] | Mutual funds [Member]
Financial Assets
Total financial assets	2,750	1,587
Short-term investments [Member] | Level II [Member] | US agency securities [Member]
Financial Assets
Total financial assets	2,002
Short-term investments [Member] | Level II [Member] | Corporate debt obligations [Member]
Financial Assets
Total financial assets	20,877
Short-term investments [Member] | Level II [Member] | Bank deposits [Member]
Financial Assets
Total financial assets	10,063
Short-term investments [Member] | Level III [Member] | Mutual funds [Member]
Financial Assets
Total financial assets
Short-term investments [Member] | Level III [Member] | US agency securities [Member]
Financial Assets
Total financial assets
Short-term investments [Member] | Level III [Member] | Corporate debt obligations [Member]
Financial Assets
Total financial assets
Short-term investments [Member] | Level III [Member] | Bank deposits [Member]
Financial Assets
Total financial assets