Fair value measurements Fair Value Hierarchy of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial assets
Available-for-sale investment securities	$ 820,648	$ 550,394
Financial liabilities
Short-term borrowings—other than bank	103,063	118,972
Other bank borrowings	328,582	290,656
Carrying or notional amount
Financial assets
Money market funds	10	10
Available-for-sale investment securities	820,648	550,394
Stock in Federal Home Loan Bank	10,678	69,302
Loans receivable, net	4,570,412	4,397,457
Mortgage servicing rights	8,444	11,540
Bank-owned life insurance	138,139	134,115
Derivative assets	22,616	30,120
Financial liabilities
Deposit liabilities	5,025,254	4,623,415
Short-term borrowings—other than bank	103,063	118,972
Other bank borrowings	328,582	290,656
Long-term debt, net—other than bank	1,586,546	1,506,546
Derivative liabilities	23,269	32,043
Estimated fair value
Financial assets
Money market funds	10	10
Available-for-sale investment securities	820,648	550,394
Stock in Federal Home Loan Bank	10,678	69,302
Loans receivable, net	4,749,525	4,578,822
Mortgage servicing rights	11,790	14,504
Bank-owned life insurance	138,139	134,115
Derivative assets	385	398
Financial liabilities
Deposit liabilities	5,024,500	4,623,773
Short-term borrowings—other than bank	103,063	118,972
Other bank borrowings	333,392	298,837
Long-term debt, net—other than bank	1,669,087	1,622,736
Derivative liabilities	30	114
Estimated fair value | Level 1
Financial assets
Derivative assets		0
Financial liabilities
Derivative liabilities	15	71
Estimated fair value | Level 2
Financial assets
Money market funds	10	10
Available-for-sale investment securities	820,648	550,394
Stock in Federal Home Loan Bank	10,678	69,302
Loans receivable, net	4,639	8,713
Bank-owned life insurance	138,139	134,115
Derivative assets	385	398
Financial liabilities
Deposit liabilities	5,024,500	4,623,773
Short-term borrowings—other than bank	103,063	118,972
Other bank borrowings	333,392	298,837
Long-term debt, net—other than bank	1,669,087	1,622,736
Derivative liabilities	15	43
Estimated fair value | Level 3
Financial assets
Loans receivable, net	4,744,886	4,570,109
Mortgage servicing rights	11,790	14,504
Hawaiian Electric Company, Inc. and Subsidiaries | Carrying or notional amount
Financial liabilities
Long-term debt, net—other than bank	1,286,546	1,206,546
Hawaiian Electric Company, Inc. and Subsidiaries | Estimated fair value
Financial liabilities
Long-term debt, net—other than bank	1,363,766	1,313,893
Hawaiian Electric Company, Inc. and Subsidiaries | Estimated fair value | Level 2
Financial liabilities
Long-term debt, net—other than bank	$ 1,363,766	$ 1,313,893