Investments - Available for sale investments (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Certificates of deposit
Amortized cost of fixed maturity investments by asset type	$ 45,162,000	$ 61,280,000
Gross unrealized gains by asset type	0	0
Gross unrealized losses by asset type	0	0
Investments at fair value	45,162,000	61,280,000
U.S. treasury securities
Amortized cost of fixed maturity investments by asset type	11,604,622	19,091,842
Gross unrealized gains by asset type	680	14,205
Gross unrealized losses by asset type	(4,270)	(2,122)
Investments at fair value	11,601,032	19,103,925
Corporate securities
Amortized cost of fixed maturity investments by asset type	15,913,043
Gross unrealized gains by asset type	31,057
Gross unrealized losses by asset type	(2,078)
Investments at fair value	15,942,022
Agency mortgage-backed securities
Amortized cost of fixed maturity investments by asset type	11,198,332
Gross unrealized gains by asset type	2,021
Gross unrealized losses by asset type	(31,283)
Investments at fair value	11,169,070
Total fixed maturities
Amortized cost of fixed maturity investments by asset type	83,877,997	80,371,842
Gross unrealized gains by asset type	33,758	14,205
Gross unrealized losses by asset type	(37,631)	(2,122)
Investments at fair value	$ 83,874,124	$ 80,383,925