Commitments and Contingencies (Details)	3 Months Ended		6 Months Ended
	Sep. 30, 2018 USD ($) item	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) item	Sep. 30, 2017 USD ($)
Commitments and Contingencies
The number of vessels with contracts to purchase exhaust gas cleaning systems | item	7		7
Commitments under Contracts for Scrubber Purchases
Less than one year	$ 3,024,231		$ 3,024,231
One to three years	2,387,551		2,387,551
Total	5,411,782		5,411,782
Operating Leases
Operating lease rent expense	106,117	$ 108,358	233,599	$ 214,550
Commitments under Operating Leases
Less than one year	422,421		422,421
One to three years	473,247		473,247
Three to five years	329,217		329,217
Total	1,224,885		1,224,885
Fixed Time Charter Contracts
Less than one year	29,578,114		29,578,114
One to three years	12,431,365		12,431,365
Total	$ 42,009,479		$ 42,009,479