Fair value measurements (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Financial assets
Available-for-sale investment and mortgage-related securities	$ 531,603,000	$ 529,007,000
Financial liabilities
Short-term borrowings—other than bank	150,576,000	105,482,000
Other bank borrowings	263,204,000	244,514,000
Carrying or notional amount
Financial assets
Money market funds	10,000	10,000
Available-for-sale investment and mortgage-related securities	531,603,000	529,007,000
Investment in stock of Federal Home Loan Bank of Seattle	75,063,000	92,546,000
Loans receivable, net	4,294,288,000	4,115,415,000
Derivative assets	17,011,000	46,356,000
Financial liabilities
Deposit liabilities	4,533,797,000	4,372,477,000
Short-term borrowings—other than bank	150,576,000	105,482,000
Other bank borrowings	263,204,000	244,514,000
Long-term debt, net-other than bank	1,517,946,000	1,492,945,000
Derivative liabilities	10,207,000	4,732,000
Carrying or notional amount | American Savings Bank (ASB)
Financial liabilities
Loan commitments and unused lines and letters of credit	1,800,000,000	1,600,000,000
Notional amount of loans serviced	1,400,000,000	1,400,000,000
Estimated fair value
Financial assets
Money market funds	10,000	10,000
Available-for-sale investment and mortgage-related securities	531,603,000	529,007,000
Investment in stock of Federal Home Loan Bank of Seattle	75,063,000	92,546,000
Loans receivable, net	4,444,869,000	4,211,290,000
Derivative assets	217,000	629,000
Financial liabilities
Deposit liabilities	4,534,177,000	4,374,377,000
Short-term borrowings—other than bank	150,576,000	105,482,000
Other bank borrowings	271,872,000	256,029,000
Long-term debt, net-other than bank	1,626,159,000	1,508,425,000
Derivative liabilities	27,000	26,000
Estimated fair value | Level 1
Financial assets
Derivative assets	0	98,000
Financial liabilities
Derivative liabilities	23,000
Estimated fair value | Level 2
Financial assets
Money market funds	10,000	10,000
Available-for-sale investment and mortgage-related securities	531,603,000	529,007,000
Investment in stock of Federal Home Loan Bank of Seattle	75,063,000	92,546,000
Derivative assets	217,000	531,000
Financial liabilities
Deposit liabilities	4,534,177,000	4,374,377,000
Short-term borrowings—other than bank	150,576,000	105,482,000
Other bank borrowings	271,872,000	256,029,000
Long-term debt, net-other than bank	1,626,159,000	1,508,425,000
Derivative liabilities	4,000	26,000
Estimated fair value | Level 3
Financial assets
Loans receivable, net	4,444,869,000	4,211,290,000
Estimated fair value | American Savings Bank (ASB)
Financial liabilities
Loan commitments and unused lines and letters of credit	500,000	200,000
Servicing rights on loans	16,100,000	15,700,000
Hawaiian Electric Company | Carrying or notional amount
Financial liabilities
Short-term Debt, Fair Value	84,987,000
Long-term debt, net-other than bank	1,217,946,000	1,217,945,000
Hawaiian Electric Company | Estimated fair value
Financial liabilities
Short-term Debt, Fair Value	84,987,000
Long-term debt, net-other than bank	1,316,380,000	1,228,966,000
Hawaiian Electric Company | Estimated fair value | Level 2
Financial liabilities
Short-term Debt, Fair Value	84,987,000
Long-term debt, net-other than bank	$ 1,316,380,000	$ 1,228,966,000