Shareholders' equity (Tables)

9 Months Ended

Sep. 30, 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)	(22,768		)	—			1,581			(21,187		)	—			85			85
Balance, September 30, 2018	$	(37,719	)	$	—		$	(25,409	)	$	(63,128	)	$	—		$	(1,134	)	$	(1,134	)
Balance, December 31, 2016	$	(7,931	)	$	(454	)	$	(24,744	)	$	(33,129	)	$	(454	)	$	132		$	(322	)
Current period other comprehensive income	2,452			454			1,003			3,909			454			67			521
Balance, September 30, 2017	$	(5,479	)	$	—		$	(23,741	)	$	(29,220	)	$	—		$	199		$	199

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

Reclassifications out of AOCI were as follows:

	Amount reclassified from AOCI
	Three months ended September 30						Nine months ended September 30						Affected line item in the
(in thousands)	2018			2017			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	5,259			3,942			15,755			11,793			See Note 8 for additional details
Impact of D&Os of the PUC included in regulatory assets	(4,725		)	(3,596		)	(14,174		)	(10,790		)	See Note 8 for additional details
Total reclassifications	$	534		$	346		$	1,581		$	1,457
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	4,753			3,618			14,259			10,857			See Note 8 for additional details
Impact of D&Os of the PUC included in regulatory assets	(4,725		)	(3,596		)	(14,174		)	(10,790		)	See Note 8 for additional details
Total reclassifications	$	28		$	22		$	85		$	521