Shareholders' equity (Tables)

3 Months Ended

Mar. 31, 2018

Equity [Abstract]

Schedule of accumulated other comprehensive income

Changes in the balances of each component of accumulated other comprehensive income/(loss) (AOCI) were as follows:

	HEI Consolidated												Hawaiian Electric Consolidated
(in thousands)	Net unrealized gains (losses) on securities			Unrealized gains (losses) on derivatives			Retirement benefit plans			AOCI			Unrealized gains (losses) on derivatives			Retirement benefit plans			AOCI
Balance, December 31, 2017	$	(14,951	)	$	—		$	(26,990	)	$	(41,941	)	$	—		$	(1,219	)	$	(1,219	)
Current period other comprehensive income (loss)	(13,297		)	—			524			(12,773		)	—			31			31
Balance, March 31, 2018	$	(28,248	)	$	—		$	(26,466	)	$	(54,714	)	$	—		$	(1,188	)	$	(1,188	)
Balance, December 31, 2016	$	(7,931	)	$	(454	)	$	(24,744	)	$	(33,129	)	$	(454	)	$	132		$	(322	)
Current period other comprehensive income	223			454			308			985			454			5			459
Balance, March 31, 2017	$	(7,708	)	$	—		$	(24,436	)	$	(32,144	)	$	—		$	137		$	137

Schedule of reclassifications out of accumulated other comprehensive income/(loss)

Reclassifications out of AOCI were as follows:

	Amount reclassified from AOCI
	Three months ended March 31						Affected line item in the
(in thousands)	2018			2017			Statements of Income / Balance Sheets
HEI consolidated
Derivatives qualifying as cash flow hedges:
Window forward contracts	$	—		$	454		Property, plant and equipment-electric utilities
Retirement benefit plans:
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost	5,146			3,921			See Note 8 for additional details
Impact of D&Os of the PUC included in regulatory assets	(4,622		)	(3,613		)	See Note 8 for additional details
Total reclassifications	$	524		$	762
Hawaiian Electric consolidated
Derivatives qualifying as cash flow hedges:
Window forward contracts	$	—		$	454		Property, plant and equipment
Retirement benefit plans:
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost	4,653			3,618			See Note 8 for additional details
Impact of D&Os of the PUC included in regulatory assets	(4,622		)	(3,613		)	See Note 8 for additional details
Total reclassifications	$	31		$	459