Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 31,866	$ 45,787
Net unrealized gains (losses) on available-for-sale investment securities:
Net unrealized gains on available-for-sale investment securities arising during the period, net of tax benefits of $2,278 and $1,664 for the respective periods	3,451	2,520
Less: reclassification adjustment for net realized gains included in net income, net of taxes of nil and $1,132 for the respective periods	0	(1,715)
Derivatives qualified as cash flow hedges:
Less: reclassification adjustment to net income, net of tax benefits of $37 for both periods	59	59
Retirement benefit plans:
Less: amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $3,486 and $1,796 for the respective periods	5,459	2,813
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $3,127 and $1,598 for the respective periods	(4,911)	(2,510)
Other comprehensive income, net of taxes	4,058	1,167
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	$ 35,924	$ 46,954