Earnings per share and shareholders' equity (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reclassifications out of accumulated other comprehensive income/(loss)
Interest expense	$ 19,456	$ 18,731
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(2,813)	(6,021)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	2,510	5,313
Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Total reclassifications	(1,353)	767
Net unrealized losses on securities | Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Revenues-bank (net gains on sales of securities)	(1,715)	0
Derivatives qualified as cash flow hedges Interest rate contracts (settled in 2011) | Interest rate contracts | Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Interest expense	59	59
Retirement benefits plans | Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	2,813	6,021
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	(2,510)	(5,313)
Hawaiian Electric Company, Inc. and Subsidiaries
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(2,519)	(5,331)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	2,510	5,313
Hawaiian Electric Company, Inc. and Subsidiaries | Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Total reclassifications	9	18
Hawaiian Electric Company, Inc. and Subsidiaries | Retirement benefits plans | Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	2,519	5,331
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	$ (2,510)	$ (5,313)