Summary of Significant Accounting Policies and Procedures - Schedule of Changes in Deferred U.S. Treasury Grant Income (Detail) - U.S. Treasury grants [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Grant [Line Items]
Beginning balance	$ 412,816	$ 427,809	$ 298,260
U.S. Treasury grants received and receivable	144	342	124,404
U.S. Treasury grants received by investors under lease pass-through fund arrangements			20,599
Amortized as a credit to depreciation expense	(15,341)	(15,335)	(15,454)
Ending balance	$ 397,619	$ 412,816	$ 427,809