Basis of Presentation (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) shares	Jun. 30, 2015 USD ($) shares	Jun. 30, 2016 USD ($) item shares	Jun. 30, 2015 USD ($) shares
Cash and Cash Equivalents
Number of banks in which the entity has its majority cash balances held in demand deposit accounts | item			1
Funds released from restricted cash account | $				$ 400
Supplemental Non-Cash Investing and Financing Activities
Accounts payable | $			$ 21,500	15,200
Taxes Collected from Customers
Excise taxes and Hawaii Public Utility Commission fees | $	$ 2,000	$ 2,000	$ 4,300	$ 4,000
Denominator used to compute basic and diluted earnings per share
Basic earnings per share - weighted average shares	11,511,591	10,797,111	11,493,712	10,744,944
Effect of dilutive securities:
Employee and director restricted stock units (in shares)	14,259	25,878	29,503	72,367
Warrants (in shares)		435,189		444,224
Diluted earnings per share - weighted average shares	11,525,850	11,258,178	11,523,215	11,261,535
Shares attributable to restricted stock units excluded from computation of weighted average dilutive shares	152,447	22,825	109,730	0