Business Segment and Geographic Region Information (Details 2) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue and long-lived assets by geographic region
Revenue	$ 44,624,000	$ 44,640,000	$ 59,114,000	$ 55,007,000	$ 60,411,000	$ 72,455,000	$ 93,380,000	$ 93,170,000	$ 203,385,000	$ 319,416,000	$ 275,212,000
Long-Lived Assets	44,192,000				55,468,000				44,192,000	55,468,000	50,974,000
International revenue, amount									142,800,000	231,000,000	208,500,000
International revenue, percentage									70.20%	72.30%	75.80%
United States
Revenue and long-lived assets by geographic region
Revenue									132,159,000	234,132,000	190,819,000
Long-Lived Assets	43,440,000				54,472,000				43,440,000	54,472,000	50,532,000
Europe
Revenue and long-lived assets by geographic region
Revenue									27,636,000	31,505,000	33,822,000
Asia Pacific
Revenue and long-lived assets by geographic region
Revenue									43,590,000	53,779,000	50,571,000
Long-Lived Assets	$ 752,000				$ 996,000				$ 752,000	$ 996,000	$ 442,000