Bank segment (HEI only) Securities Sold Under Agreements to Repurchase, Including Related Collateral Received From or Pledged to Counterparties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Securities sold under agreements to repurchase
Gross amount of recognized liabilities, repurchase agreements	$ 191,000	$ 145,000
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	191,000	145,000
Financial instruments	191,000	145,000
Identical securities
Securities sold under agreements to repurchase
Repurchase liability	190,656	145,000	$ 146,000
Average amount outstanding during the year	155,000	147,000	173,000
Maximum amount outstanding as of any month-end	$ 195,000	$ 151,000	$ 189,000
Weighted-average interest rate as of end of the period (as a percent)	1.45%	1.75%	1.74%
Weighted-average interest rate during the year (as a percent)	1.67%	1.74%	1.56%
Weighted-average remaining days to maturity as of end of the period	343 days	367 days	489 days
Overnight
Securities sold under agreements to repurchase
Repurchase liability	$ 84,758
Weighted-average interest rate as of end of the period (as a percent)	0.15%
1 to 29 days
Securities sold under agreements to repurchase
Repurchase liability	$ 0
Weighted-average interest rate as of end of the period (as a percent)	0.00%
30 to 90 days
Securities sold under agreements to repurchase
Repurchase liability	$ 0
Weighted-average interest rate as of end of the period (as a percent)	0.00%
Over 90 days
Securities sold under agreements to repurchase
Repurchase liability	$ 105,898
Weighted-average interest rate as of end of the period (as a percent)	2.50%
Financial institution
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	$ 50,000	$ 51,000
Financial instruments	50,000	51,000
Government entities
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	56,000
Financial instruments	56,000
Commercial account holders
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	85,000	94,000
Financial instruments	$ 85,000	$ 94,000