Segment Information - Long-lived Assets Including Property, Plant and Equipment and Project Assets Noncurrent by Geographic Location (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	$ 140,906	$ 127,703
UNITED STATES
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	16,121	11,630
GREECE
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	60,454	68,708
CHINA
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	52,507	46,872
JAPAN
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	1,492	493
ITALY
Schedule of Segmentinformation Details Net Salesby Geographic Location [Line Items]
Long-lived assets	$ 10,332