v2.4.0.6
Equity method investments (Details 2) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Assets      
Total assets $ 644,485 $ 700,680 $ 546,219
Liabilities      
Total liabilities 215,795 226,329 251,414
Operating results      
Project revenue 216,451 195,813 197,723
Project expenses 174,147 174,459 167,867
Project other income (expense) (27,058) (14,998) (16,079)
Project income (loss) 15,246 6,356 13,777
Chambers
      
Assets      
Current assets 16,143 9,937 11,391
Non-Current assets 235,151 245,842 253,388
Liabilities      
Current liabilities 15,188 16,016 15,914
Non-Current liabilities 81,806 95,966 109,010
Operating results      
Project revenue 58,077 49,336 55,469
Project expenses 39,094 39,358 38,377
Project other income (expense) (1,901) (2,239) (3,948)
Project income (loss) 17,082 7,739 13,144
Orlando
      
Assets      
Current assets 6,997 6,892 6,965
Non-Current assets 18,104 23,805 29,419
Liabilities      
Current liabilities 5,171 4,742 4,841
Operating results      
Project revenue 43,272 40,345 42,062
Project expenses 39,989 39,414 39,898
Project other income (expense) (83) (68) (133)
Project income (loss) 3,200 863 2,031
Gregory
      
Assets      
Current assets 3,238 3,933 3,063
Non-Current assets 14,636 16,092 19,490
Liabilities      
Current liabilities 4,023 3,132 3,421
Non-Current liabilities 11,055 13,373 15,470
Operating results      
Project revenue 20,986 28,474 31,291
Project expenses 21,394 27,440 27,324
Project other income (expense) (317) (510) (1,805)
Project income (loss) (725) 524 2,162
Koma Kulshan Associates
      
Operating results      
Project income (loss) 537 483 452
Frederickson
      
Operating results      
Project income (loss) 886 444  
Onondaga Renewables, LLC
      
Operating results      
Project income (loss) (433) (1,761) (320)
Idaho Wind Partners 1, LLC
      
Operating results      
Project income (loss) (193) (1,563) (126)
Selkirk
      
Assets      
Current assets 12,854 15,852 11,782
Non-Current assets 25,958 47,737 65,036
Liabilities      
Current liabilities 4,837 14,743 17,371
Non-Current liabilities 275 1,489 5,872
Operating results      
Project revenue 48,660 54,613 51,915
Project expenses 42,383 49,595 48,496
Project other income (expense) 1,363 (5,424) (6,873)
Project income (loss) 7,640 (406) (3,454)
Badger Creek
      
Assets      
Current assets   766 2,714
Non-Current assets   6,011 6,645
Liabilities      
Current liabilities   300 1,520
Operating results      
Project revenue 3,357 6,546 13,485
Project expenses 2,971 6,526 11,723
Project other income (expense) (3,164) (24) (1,013)
Project income (loss) (2,778) (4) 749
Rockland Wind Farm
      
Operating results      
Project income (loss) (4,183)    
PERH
      
Operating results      
Project income (loss) (1,974) 38  
Other
      
Assets      
Current assets 21,823 10,671 7,563
Non-Current assets 289,581 313,142 128,763
Liabilities      
Current liabilities 7,163 10,980 76,910
Non-Current liabilities 86,277 65,588 1,085
Operating results      
Project revenue 42,099 16,499 3,501
Project expenses 28,316 12,126 2,049
Project other income (expense) (22,956) (6,733) (2,307)
Project income (loss) $ (9,173) $ (2,360) $ (855)