Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 68,683,505	$ 76,516,110
Accounts receivable	11,261,855	5,089,708
Prepaid expenses	3,065,114	3,093,962
Inventories	12,570,540	10,876,713
Vessels held for sale	15,210,204	8,688,601
Other current assets	1,217,330	22
Total current assets	112,008,548	104,265,116
Noncurrent assets:
Vessels and vessel improvements, at cost, net of accumulated depreciation of $86,324,808 and $76,463,743, respectively	662,179,523	567,592,950
Advances for vessels purchase	20,863,466	1,926,886
Other fixed assets, net of accumulated amortization of $382,736 and $307,880, respectively	760,811	632,805
Restricted cash	74,917	74,917
Deferred drydock costs, net	9,873,520	11,507,309
Other assets	1,026,744	381,634
Total noncurrent assets	694,778,981	582,116,501
Total assets	806,787,529	686,381,617
Current liabilities:
Accounts payable	7,841,063	7,135,156
Accrued interest	13,655	28,872
Other accrued liabilities	8,114,876	11,545,447
Fair value below contract value of time charters acquired		820,313
Unearned charter hire revenue	6,415,987	6,046,032
Total current liabilities	22,385,581	25,575,820
Noncurrent liabilities:
Total debt	297,036,461	255,943,544
Other liabilities	320,046	483,132
Fair value below contract value of time charters acquired	2,840,962	3,896,482
Total noncurrent liabilities	300,197,469	260,323,158
Total liabilities	322,583,050	285,898,978
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 25,000,000 shares authorized, none issued as of June 30, 2017 and December 31, 2016, respectively
Common stock, $0.01 par value, 700,000,000 shares authorized, 70,329,050 and 48,106,827 shares issued and outstanding as of June 30, 2017 and December 31, 2016, respectively	703,291	481,069
Additional paid-in capital	883,826,230	783,369,698
Accumulated deficit	(400,325,042)	(383,368,128)
Total stockholders’ equity	484,204,479	400,482,639
Total liabilities and stockholders’ equity	806,787,529	686,381,617
First Lien Facility [Member]
Noncurrent liabilities:
Total debt	199,913,956	204,352,318
Second Lien Facility [Member]
Noncurrent liabilities:
Total debt	58,615,505	51,591,226
Ultraco Debt Facility [Member]
Noncurrent liabilities:
Total debt	$ 38,507,000