Deferred Tax Liability, Net (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Summary of deferred tax liability
Deferred tax asset - current (accrual of employee social insurance)	$ 168,898	$ 167,980
Deferred tax liability - current (net investment in sales-type leases)	(1,653,909)	(1,586,058)
Deferred tax liability, net of current deferred tax asset	(1,485,011)	(1,418,078)
Deferred tax asset - noncurrent (depreciation of fixed assets)	17,610,849	17,943,843
Deferred tax liability - noncurrent (net investment in sales-type leases)	(25,152,388)	(25,426,744)
Deferred tax liability, net of noncurrent deferred tax asset	(7,541,539)	(7,482,901)
Total Deferred tax liability, noncurrent	$ 9,026,550	$ 8,900,979