Financial Instruments and Fair Value Disclosures (Carrying and FV) (Details) - USD ($)	Jun. 30, 2020	Mar. 31, 2020
Fair value
Carrying Value	$ 647,513,988	$ 634,975,219
US Treasury Bills
Fair value
Carrying Value	15,000,000.0
Corsair Japanese Financing
Fair value
Carrying Value	43,333,333	44,145,833
Corsair Japanese Financing | Level 2
Fair value
Fair Value	48,385,962	48,867,762
Concorde Japanese Financing
Fair value
Carrying Value	47,923,077	48,730,769
Concorde Japanese Financing | Level 2
Fair value
Fair Value	53,983,226	54,407,677
Corvette Japanese Financing
Fair value
Carrying Value	48,461,538	49,269,231
Corvette Japanese Financing | Level 2
Fair value
Fair Value	54,648,430	55,059,323
CJNP Japanese Financing
Fair value
Carrying Value	18,696,875	19,058,750
CJNP Japanese Financing | Level 2
Fair value
Fair Value	20,660,143	21,006,399
CMNL Japanese Financing
Fair value
Carrying Value	17,734,078	18,076,488
CMNL Japanese Financing | Level 2
Fair value
Fair Value	19,935,753	20,238,260
CNML Japanese Financing
Fair value
Carrying Value	19,909,673	20,261,012
CNML Japanese Financing | Level 2
Fair value
Fair Value	$ 22,426,002	$ 22,728,984