Cash and Cash Equivalents - Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 44,602	$ 44,593	$ 41,216	$ 29,372
United States [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	15,850	2,741
Asia [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	19,113	27,317
Europe [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	6,615	9,361
Cayman Islands [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	8	1
South America [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 3,016	$ 5,173