9. Accumulated Other Comprehensive Loss

Accumulated other comprehensive loss is defined as the revenues, expenses, gains and losses that are included in comprehensive income but excluded from net income. The Company’s significant items of accumulated other comprehensive loss are pension and other benefits, net unrealized gains or losses on investment securities and net unrealized gains or losses on cash flow derivative hedges.

Changes in accumulated other comprehensive loss for the three months ended March 31, 2019 and 2018 are presented below:


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at December 31, 2018	$	(180,915)	$	48,720	$	(132,195)
Three months ended March 31, 2019
Investment securities:
Unrealized net gains arising during the period		70,523		(18,991)		51,532
Reclassification of net losses to net income:
Investment securities losses, net		2,613		(704)		1,909
Net change in investment securities		73,136		(19,695)		53,441
Other comprehensive income		73,136		(19,695)		53,441
Accumulated other comprehensive loss at March 31, 2019	$	(107,779)	$	29,025	$	(78,754)


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at December 31, 2017	$	(159,423)	$	63,040	$	(96,383)
Three months ended March 31, 2018
Early adoption of ASU No. 2018-02		—		(20,068)		(20,068)
Investment securities:
Unrealized net losses arising during the period		(66,700)		17,923		(48,777)
Net change in investment securities		(66,700)		17,923		(48,777)
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		738		(194)		544
Net change in cash flow derivative hedges		738		(194)		544
Other comprehensive loss		(65,962)		17,729		(48,233)
Accumulated other comprehensive loss at March 31, 2018	$	(225,385)	$	60,701	$	(164,684)

The following table summarizes changes in accumulated other comprehensive loss, net of tax, for the periods indicated:


							Total
	Pensions						Accumulated
	and						Other
	Other		Investment		Cash Flow		Comprehensive
(dollars in thousands)	Benefits		Securities		Derivative Hedges		Loss
Three Months Ended March 31, 2019
Balance at beginning of period	$	(28,379)	$	(103,816)	$	—	$	(132,195)
Other comprehensive income		—		53,441		—		53,441
Balance at end of period	$	(28,379)	$	(50,375)	$	—	$	(78,754)

Three Months Ended March 31, 2018
Balance at beginning of period	$	(25,946)	$	(74,117)	$	3,680	$	(96,383)
Early adoption of ASU No. 2018-02		(5,393)		(15,440)		765		(20,068)
Other comprehensive (loss) income		—		(48,777)		544		(48,233)
Balance at end of period	$	(31,339)	$	(138,334)	$	4,989	$	(164,684)