Equity Incentive Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Options
Options Outstanding, Beginning of Period (in shares)	1,470,043	1,529,300	1,529,300
Exercised (in shares)	3,900	0
Forfeited (in shares)	24,700	0
Expired (in shares)	43,273	0
Options Outstanding, End of period (in shares)	1,398,170	1,529,300	1,470,043	1,529,300
Exercisable (in shares)	986,670	829,400
Weighted- average exercise price
Options Outstanding, Beginning of Period (in usd per share)	$ 15.22	$ 14.50	$ 14.50
Exercised (in usd per share)	14.37	0.00
Forfeited (in usd per share)	14.43	0.00
Expired (in usd per share)	23.82	0.00
Options Outstanding, End of Period (in usd per share)	14.97	14.50	$ 15.22	$ 14.50
Exercisable (in usd per share)	$ 14.43	$ 14.40
Remaining contractual life (years)	5 years 4 months 25 days	6 years 4 months	5 years 9 months 18 days	6 years 9 months 18 days
Aggregate intrinsic value (in usd)	$ 15,077	$ 17,433	$ 13,533	$ 6,117
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 2 months 12 days
Aggregate intrinsic value (in usd)	$ 11,169
Non-vested Options
Nonvested, number of shares (in shares)	411,500
Nonvested, weighted average grant date fair value (in dollars per share)	$ 16.25
Nonvested, contractual term (in years)	6 years
Nonvested, intrinsic value	$ 3,908