Business Segment and Foreign Operations - Long-lived Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	$ 81,758	$ 83,067
United States [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	4,786	5,541
People's Republic of China [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	73,751	73,804
All Other Countries [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	$ 3,221	$ 3,722