Borrowings (Components of long-term debt) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current	$ 12,599	$ 11,996
Long-term	145,074	152,574
Total	157,673	164,570
Estimated fair value of long-term debt	176,049	182,602
Capital Lease Obligations [Member]
Current	2,405	2,574
Long-term	57,374	59,024
Total	59,779	61,598
Secured Debt-FW Power Srl [Member]
Current	8,282	7,403
Long-term	77,109	81,047
Total	85,391	88,450
Secured Debt - Energia Holdings [Member]
Current	1,912	2,019
Long-term	9,308	11,220
Total	11,220	13,239
1999C Bonds [Member]
Current	0	0
Long-term	1,283	1,283
Total	$ 1,283	$ 1,283