Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income/(loss)	$ 52,745	$ (11,068,448)
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:
Depreciation	8,073,353	6,510,735
Amortization of deferred drydocking costs	1,203,062	982,073
Amortization of debt issuance costs	490,095	1,444,963
Amortization of fair value below contract value of time charter acquired	(170,475)	(205,078)
Payment-in-kind interest on debt	0	2,334,893
Net unrealized loss on fair value of derivative instruments	208,235	293,007
Stock-based compensation expense	3,510,911	2,170,700
Drydocking expenditures	(1,107,414)	(25,807)
Gain on sale of vessel	0	(92,114)
Changes in operating assets and liabilities:
Accounts receivable	3,270,432	(3,676,803)
Other current and non-current assets	(121,954)	(426,860)
Prepaid expenses	(652,271)	502,054
Inventories	490,738	2,148,742
Accounts payable	1,544,461	(249,235)
Accrued interest	4,122,188	(28,872)
Other accrued and other non-current liabilities	(5,009,784)	(3,738,154)
Unearned revenue	(1,031,082)	1,114,886
Net cash provided by/(used in) operating activities	14,873,240	(2,009,318)
Cash flows from investing activities:
Purchase of vessels and vessel improvements	(19,841,535)	(17,297,323)
Advance paid for purchase of vessel	0	(10,320,000)
Proceeds from redemption of Short-term investment	4,500,000	0
Proceeds from sale of vessels	0	5,790,500
Purchase of other fixed assets	966	(47,008)
Net cash used in investing activities	(15,340,569)	(21,873,831)
Cash flows from financing activities:
Proceeds from the common stock private placement, net of issuance costs	0	96,030,003
Cash used to settle net share equity awards	(254,146)	0
Other financing costs	(1,231,935)	0
Net cash provided by financing activities	2,113,919	93,134,753
Net increase in cash and cash equivalents and restricted cash	1,646,590	69,251,604
Cash and cash equivalents and restricted cash at beginning of period	56,325,961	76,591,027
Cash and cash equivalents and restricted cash at end of period	57,972,551	145,842,631
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid during the year for interest	1,648,787	2,694,046
Ultraco Debt Facility
Cash flows from financing activities:
Proceeds from Ultraco Debt Facility	8,600,000	0
Term Loan
Cash flows from financing activities:
Repayments of lines of credit	0	(2,895,250)
Revolver Loan
Cash flows from financing activities:
Repayments of lines of credit	$ (5,000,000)	$ 0