Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies- Project Assets (Details)

v2.4.0.8
Summary of Significant Accounting Policies- Project Assets (Details) (USD $)
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Dec. 31, 2013
Accounting Policies [Abstract]          
Interest costs capitalized $ 0 $ 250,000 $ 395,000 $ 715,000  
Minimum qualifying operating period for prorated repayments of grants     5 years    
Amounts received from grants 3,727,000 289,000 3,727,000 1,580,000  
Deferred grant income $ 9,118,000   $ 9,118,000   $ 8,163,000