Investments - Available for sale investments (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Certificates of deposit
Amortized cost of fixed maturity investments by asset type	$ 35,826,000	$ 61,280,000
Gross unrealized gains by asset type	0	0
Gross unrealized losses by asset type	0	0
Investments at fair value	35,826,000	61,280,000
U.S. treasury securities
Amortized cost of fixed maturity investments by asset type	9,528,210	19,091,842
Gross unrealized gains by asset type	248	14,205
Gross unrealized losses by asset type	(9,395)	(2,122)
Investments at fair value	9,519,063	19,103,925
Corporate securities
Amortized cost of fixed maturity investments by asset type	22,983,627
Gross unrealized gains by asset type	49,063
Gross unrealized losses by asset type	(36,981)
Investments at fair value	22,995,709
Agency mortgage-backed securities
Amortized cost of fixed maturity investments by asset type	15,941,512
Gross unrealized gains by asset type	3,754
Gross unrealized losses by asset type	(17,143)
Investments at fair value	15,928,123
Total fixed maturities
Amortized cost of fixed maturity investments by asset type	84,279,349	80,371,842
Gross unrealized gains by asset type	53,065	14,205
Gross unrealized losses by asset type	(63,519)	(2,122)
Investments at fair value	$ 84,268,895	$ 80,383,925