10. 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 and nine months ended September 30, 2018 and 2017 are presented below:


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at June 30, 2018	$	(249,648)	$	67,238	$	(182,410)
Three months ended September 30, 2018
Investment securities:
Unrealized net losses arising during the period		(30,682)		8,262		(22,420)
Net change in unrealized losses on investment securities		(30,682)		8,262		(22,420)
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		178		(47)		131
Net change in unrealized gains on cash flow derivative hedges		178		(47)		131
Other comprehensive loss		(30,504)		8,215		(22,289)
Accumulated other comprehensive loss at September 30, 2018	$	(280,152)	$	75,453	$	(204,699)


			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)
Nine months ended September 30, 2018
Early adoption of ASU No. 2018-02		—		(20,068)		(20,068)
Investment securities:
Unrealized net losses arising during the period		(122,070)		32,834		(89,236)
Net change in unrealized losses on investment securities		(122,070)		32,834		(89,236)
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		1,341		(353)		988
Net change in unrealized gains on cash flow derivative hedges		1,341		(353)		988
Other comprehensive loss		(120,729)		32,481		(88,248)
Accumulated other comprehensive loss at September 30, 2018	$	(280,152)	$	75,453	$	(204,699)


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at June 30, 2017	$	(111,823)	$	44,172	$	(67,651)
Three months ended September 30, 2017
Investment securities:
Unrealized net gains arising during the period		212		(84)		128
Net change in unrealized gains on investment securities		212		(84)		128
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		675		(266)		409
Net change in unrealized gains on cash flow derivative hedges		675		(266)		409
Other comprehensive income		887		(350)		537
Accumulated other comprehensive loss at September 30, 2017	$	(110,936)	$	43,822	$	(67,114)


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at December 31, 2016	$	(145,472)	$	57,461	$	(88,011)
Nine months ended September 30, 2017
Investment securities:
Unrealized net gains arising during the period		33,005		(13,035)		19,970
Net change in unrealized gains on investment securities		33,005		(13,035)		19,970
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		1,531		(604)		927
Net change in unrealized gains on cash flow derivative hedges		1,531		(604)		927
Other comprehensive income		34,536		(13,639)		20,897
Accumulated other comprehensive loss at September 30, 2017	$	(110,936)	$	43,822	$	(67,114)

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


							Total
	Pensions		Unrealized		Unrealized		Accumulated
	and		(Losses) Gains		Gains on		Other
	Other		on Investment		Cash Flow		Comprehensive
(dollars in thousands)	Benefits		Securities		Derivative Hedges		Loss
Three Months Ended September 30, 2018
Balance at beginning of period	$	(31,339)	$	(156,373)	$	5,302	$	(182,410)
Other comprehensive (loss) income		—		(22,420)		131		(22,289)
Balance at end of period	$	(31,339)	$	(178,793)	$	5,433	$	(204,699)

Nine Months Ended September 30, 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		—		(89,236)		988		(88,248)
Balance at end of period	$	(31,339)	$	(178,793)	$	5,433	$	(204,699)

Three Months Ended September 30, 2017
Balance at beginning of period	$	(30,237)	$	(40,116)	$	2,702	$	(67,651)
Other comprehensive income		—		128		409		537
Balance at end of period	$	(30,237)	$	(39,988)	$	3,111	$	(67,114)

Nine Months Ended September 30, 2017
Balance at beginning of period	$	(30,237)	$	(59,958)	$	2,184	$	(88,011)
Other comprehensive income		—		19,970		927		20,897
Balance at end of period	$	(30,237)	$	(39,988)	$	3,111	$	(67,114)