Bank segment (HEI only) Statements of Comprehensive Income- Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net unrealized gains (losses) on securities arising during the period, taxes	$ 1,541	$ (3,856)	$ 9,037
Less: reclassification adjustment for net realized gains included in net income, taxes	0	(1,132)	(488)
Net gains (losses) arising during the period, tax benefits	(3,753)	149,364	(142,478)
Less: amortization of net loss, prior service gain and transition obligation included in net periodic benefit cost, tax benefits	(14,344)	(7,245)	(14,870)
American Savings Bank (ASB)
Net unrealized gains (losses) on securities arising during the period, taxes	1,541	(3,856)	9,037
Less: reclassification adjustment for net realized gains included in net income, taxes	0	1,132	488
Net gains (losses) arising during the period, tax benefits	(59)	6,164	(10,450)
Less: amortization of net loss, prior service gain and transition obligation included in net periodic benefit cost, tax benefits	$ 1,011	$ 561	$ 1,187