Comprehensive income (loss) (Tables)

3 Months Ended

Mar. 31, 2017

Equity [Abstract]

Comprehensive income (loss)

The after-tax changes in the components of accumulated other comprehensive loss were as follows:

Three Months Ended March 31, 2017	Net Unrealized Gain (Loss) on Derivative  Instruments  Qualifying as Hedges			Postretirement  Liability Adjustment			Foreign Currency Translation Adjustment			Net Unrealized Gain (Loss) on Available-for-sale Investments			Total Accumulated  Other Comprehensive  Loss
	(In thousands)
Balance at beginning of period	$	(2,300	)	$	(33,221	)	$	(149	)	$	(63	)	$	(35,733	)
Other comprehensive income (loss) before reclassifications	—			—			9			(27		)	(18		)
Amounts reclassified from accumulated other comprehensive loss	91			357			—			35			483
Amounts reclassified to accumulated other comprehensive loss from a regulatory asset	—			(917		)	—			—			(917		)
Net current-period other comprehensive income (loss)	91			(560		)	9			8			(452		)
Balance at end of period	$	(2,209	)	$	(33,781	)	$	(140	)	$	(55	)	$	(36,185	)

Three Months Ended March 31, 2016	Net Unrealized Gain (Loss) on Derivative  Instruments  Qualifying as Hedges			Postretirement  Liability Adjustment			Foreign Currency Translation Adjustment			Net Unrealized Gain (Loss) on Available-for-sale Investments			Total Accumulated  Other Comprehensive  Loss
	(In thousands)
Balance at beginning of period	$	(2,667	)	$	(34,257	)	$	(200	)	$	(24	)	$	(37,148	)
Other comprehensive income before reclassifications	—			—			25			8			33
Amounts reclassified from accumulated other comprehensive loss	92			(1,595		)	—			36			(1,467		)
Net current-period other comprehensive income (loss)	92			(1,595		)	25			44			(1,434		)
Balance at end of period	$	(2,575	)	$	(35,852	)	$	(175	)	$	20		$	(38,582	)

Reclassification out of accumulated other comprehensive income

Reclassifications out of accumulated other comprehensive loss were as follows:

	Three Months Ended						Location on Consolidated Statements of Income
	March 31,
	2017			2016
	(In thousands)
Reclassification adjustment for loss on derivative instruments included in net income	$	(147	)	$	(149	)	Interest expense
	56			57			Income taxes
	(91		)	(92		)
Amortization of postretirement liability gains (losses) included in net periodic benefit cost	(574		)	2,564			(a)
	217			(969		)	Income taxes
	(357		)	1,595
Reclassification adjustment for loss on available-for-sale investments included in net income	(54		)	(55		)	Other income
	19			19			Income taxes
	(35		)	(36		)
Total reclassifications	$	(483	)	$	1,467

(a) Included in net periodic benefit cost. For more information, see Note 14.