Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Revenue Recognition) (Details)

v2.4.0.6
Summary of Significant Accounting Policies (Revenue Recognition) (Details) (USD $)
In Thousands, unless otherwise specified
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
Accounting Policies [Line Items]                      
Collaborative research and development $ 1,078 $ 18,569 $ 15,868 $ 14,612 $ 17,296 $ 19,201 $ 17,385 $ 17,486 $ 50,127 $ 71,368 $ 70,196
Sales revenue 6,834 7,140 6,783 15,167 15,493 12,199 8,397 12,932 35,924 49,021 32,835
Milestones [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 1,000 5,600 7,800
Shell [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 45,320 63,179 66,148
Shell [Member] | License, technology access and exclusivity fees [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 3,403 4,084 4,084
Shell [Member] | Services [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 41,917 53,541 54,664
Shell [Member] | Milestones [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 0 5,554 7,400
Other [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 4,807 8,189 4,048
Other [Member] | License, technology access and exclusivity fees [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 186 686 186
Other [Member] | Services [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 1,785 5,804 2,695
Other [Member] | Milestones [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 1,000 0 420
Other [Member] | Royalty [Member]
                     
Accounting Policies [Line Items]                      
Collaborative research and development                 $ 1,836 $ 1,699 $ 747