Short-Term Borrowings (Details) (USD $)	Dec. 31, 2011
Line of Credit, Foreign
Line of Credit Facility [Line Items]
Lines of credit	$ 20,200,000
Amounts drawn upon line of credit	2,800,000
Line of Credit, Domestic
Line of Credit Facility [Line Items]
Amounts drawn upon line of credit	0
Line of Credit, Domestic | Union Bank of California, Unsecured Revolving Credit Account
Line of Credit Facility [Line Items]
Lines of credit	$ 40,000,000