UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Revenues	$ 301,466,007	$ 310,453,033
Cost of revenues	(251,136,339)	(256,585,577)
Gross profit	50,329,668	53,867,456
Selling expenses	(277,820)	(1,051,009)
General and administrative expenses	(8,775,385)	(8,875,009)
Research and development expenses	(10,062,186)	(5,049,898)
Total operating expenses	(19,115,391)	(14,975,916)
Operating income	31,214,277	38,891,540
Interest income	435,779	2,312,623
Interest expense	(17,500,277)	(12,894,205)
Foreign currency exchange losses	(2,140,865)	(3,955,808)
Losses on foreign currency option contracts		(520,981)
Gains on disposal of a subsidiary	518,491
Government grant	2,094,937	1,477,559
Total non-operating expense, net	(16,591,935)	(13,580,812)
Income before income taxes	14,622,342	25,310,728
Income tax expense	(3,641,627)	(6,210,827)
Net income	$ 10,980,715	$ 19,099,901
Earnings per common share:
Basic and diluted	$ 0.16	$ 0.29
Net income	$ 10,980,715	$ 19,099,901
Other comprehensive income
Foreign currency translation adjustment, net of nil income taxes	14,670,801	29,661,410
Comprehensive income	$ 25,651,516	$ 48,761,311