Note 2 - Summary of Significant Accounting Policies - Variable Interest Entities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Current assets	$ 151,419,617	$ 59,042,764
Total assets	802,843,794	82,476,407
Current liabilities	110,445,754	33,588,305
Total liabilities	195,187,062	48,014,925
Net revenue	388,162,281	291,006,698
Net income	5,895,286	6,353,695
Net cash provided by operating activities	4,666,528	11,953,466
Net cash used in financing activities	1,607,239	(6,184,793)
Net decrease in cash and cash equivalents	9,048,882	(596,640)
Variable Entity [Member]
Current assets	158,184
Non-current assets	301,803
Total assets	459,987
Current liabilities	805,666
Non-current liabilities	69,321
Total liabilities	874,987
Net revenue	420,163
Net income	68,449
Net cash provided by operating activities	201,885
Net cash used in financing activities	(207,159)
Net decrease in cash and cash equivalents	$ (5,274)