Stockholders' Equity - Narrative (Details)				3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 13, 2017 shares	Mar. 08, 2017 USD ($) $ / shares shares	Feb. 13, 2013 $ / shares shares	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2016 shares	Jun. 30, 2017 USD ($) Vote $ / shares shares	Jun. 30, 2016 shares	Dec. 31, 2016 USD ($) $ / shares shares	May 19, 2017 USD ($)	Feb. 01, 2014 shares
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)				5,000,000		5,000,000		5,000,000
Preferred stock, par value (in USD per share) | $ / shares				$ 0.001		$ 0.001		$ 0.001
Treasury stock, shares (in shares)				131,171		131,171		119,544
Treasury stock, carrying cost | $				$ 1,307,000		$ 1,307,000		$ 1,122,000
Number of shares transferred to treasury (in shares)					2,399	11,627	6,531
Registration Statement, maximum potential consideration | $									$ 150,000,000
Treasury Stock
Class of Stock [Line Items]
Issuance of common stock (in shares)								(20,697)
Number of shares transferred to treasury (in shares)						(11,627)		(21,397)
Treasury Stock | Forfeitures of Restricted Stock Awards
Class of Stock [Line Items]
Number of shares acquired during the period (in shares)				0	3,200		3,200
Class A Common Stock
Class of Stock [Line Items]
Issuance of common stock (in shares)	3,000,000	3,000,000
Common stock, par value (in USD per share) | $ / shares				$ 0.001		$ 0.001		$ 0.001
Share price (in USD per share) | $ / shares		$ 14.00
Common stock, shares authorized (in shares)		3,000,000		100,000,000		100,000,000		100,000,000		8,566,667
Common stock votes per share | Vote						1
Proceeds from issuance of stock | $		$ 39,500,000
Share price net of underwriting discount (in USD per share) | $ / shares		$ 13.16
Class A Common Stock | Treasury Stock
Class of Stock [Line Items]
Number of shares acquired during the period (in shares)					1,623		15,280
Class A Common Stock | HII
Class of Stock [Line Items]
Total membership interest without voting right				76.40%		76.40%
Percentage of voting interests						100.00%
Class A Common Stock | IPO
Class of Stock [Line Items]
Issuance of common stock (in shares)			4,666,667
Common stock, par value (in USD per share) | $ / shares			$ 0.001
Share price (in USD per share) | $ / shares			$ 14.00
Class B Common Stock
Class of Stock [Line Items]
Common stock, par value (in USD per share) | $ / shares				$ 0.001		$ 0.001		$ 0.001
Common stock, shares authorized (in shares)				20,000,000		20,000,000		20,000,000
Common stock votes per share | Vote						1
Class B Common Stock | HII
Class of Stock [Line Items]
Common stock voting rights percentage						23.60%
Economic interest						0.00%
Class B Common Stock | IPO
Class of Stock [Line Items]
Issuance of common stock (in shares)			8,666,667
Class B Common Stock | IPO | Health Plan Intermediaries, LLC
Class of Stock [Line Items]
Issuance of common stock (in shares)			8,580,000
Class B Common Stock | IPO | HPIS
Class of Stock [Line Items]
Issuance of common stock (in shares)			86,667
Series B Membership Interests
Class of Stock [Line Items]
Number of shares acquired during the period (in shares)		3,000,000