Unaudited Seleted Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Table Text Block]

The following is a summary of the unaudited quarterly results of operations:

	2017 Quarter
​(in thousands, except per share data)	First		Second		Third		Fourth
Gross written premiums	$	52,862	$	57,753	$	55,633	$	56,943
Total revenues	42,687		45,508		47,839		50,742
Net income	6,281		8,495		4,201		5,924
Comprehensive income	7,354		10,669		5,840		7,422
Earnings per share - basic	$	0.30	$	0.41	$	0.20	$	0.28
Earnings per share - diluted	$	0.29	$	0.40	$	0.20	$	0.27

	2016 Quarter
​(in thousands, except per share data)	First		Second		Third		Fourth
Gross written premiums	$	43,082	$	50,107	$	47,823	$	47,466
Total revenues	32,718		33,676		34,868		40,353
Net income	5,257		6,057		7,982		6,871
Comprehensive income	7,383		8,947		7,981		1,216
Earnings per share - basic:
Common stock	$	—	$	—	$	0.24	$	0.33
Class A common stock	0.37		0.42		0.19		—
Class B common stock	0.07		0.19		0.21		—
Earnings per share - diluted:
Common stock	$	—	$	—	$	0.24	$	0.32
Class A common stock	0.37		0.42		0.19		—
Class B common stock	0.07		0.18		0.20		—