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 and six months ended June 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 March 31, 2018	$	(225,385)	$	60,701	$	(164,684)
Three months ended June 30, 2018
Investment securities:
Unrealized net losses arising during the period		(24,688)		6,649		(18,039)
Net change in unrealized losses on investment securities		(24,688)		6,649		(18,039)
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		425		(112)		313
Net change in unrealized gains on cash flow derivative hedges		425		(112)		313
Other comprehensive loss		(24,263)		6,537		(17,726)
Accumulated other comprehensive loss at June 30, 2018	$	(249,648)	$	67,238	$	(182,410)


			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)
Six months ended June 30, 2018
Early adoption of ASU No. 2018-02		—		(20,068)		(20,068)
Investment securities:
Unrealized net losses arising during the period		(91,388)		24,572		(66,816)
Net change in unrealized losses on investment securities		(91,388)		24,572		(66,816)
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		1,163		(306)		857
Net change in unrealized gains on cash flow derivative hedges		1,163		(306)		857
Other comprehensive loss		(90,225)		24,266		(65,959)
Accumulated other comprehensive loss at June 30, 2018	$	(249,648)	$	67,238	$	(182,410)


			Income
			Tax
	Pre-tax		Benefit		Net of
(dollars in thousands)	Amount		(Expense)		Tax
Accumulated other comprehensive loss at March 31, 2017	$	(143,296)	$	56,604	$	(86,692)
Three months ended June 30, 2017
Investment securities:
Unrealized net gains arising during the period		31,215		(12,330)		18,885
Net change in unrealized gains on investment securities		31,215		(12,330)		18,885
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		258		(102)		156
Net change in unrealized gains on cash flow derivative hedges		258		(102)		156
Other comprehensive income		31,473		(12,432)		19,041
Accumulated other comprehensive loss at June 30, 2017	$	(111,823)	$	44,172	$	(67,651)


			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)
Six months ended June 30, 2017
Investment securities:
Unrealized net gains arising during the period		32,793		(12,951)		19,842
Net change in unrealized gains on investment securities		32,793		(12,951)		19,842
Cash flow derivative hedges:
Unrealized net gains on cash flow derivative hedges arising during the period		856		(338)		518
Net change in unrealized gains on cash flow derivative hedges		856		(338)		518
Other comprehensive income		33,649		(13,289)		20,360
Accumulated other comprehensive loss at June 30, 2017	$	(111,823)	$	44,172	$	(67,651)

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 June 30, 2018
Balance at beginning of period	$	(31,339)	$	(138,334)	$	4,989	$	(164,684)
Other comprehensive (loss) income		—		(18,039)		313		(17,726)
Balance at end of period	$	(31,339)	$	(156,373)	$	5,302	$	(182,410)

Six Months Ended June 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		—		(66,816)		857		(65,959)
Balance at end of period	$	(31,339)	$	(156,373)	$	5,302	$	(182,410)

Three Months Ended June 30, 2017
Balance at beginning of period	$	(30,237)	$	(59,001)	$	2,546	$	(86,692)
Other comprehensive income		—		18,885		156		19,041
Balance at end of period	$	(30,237)	$	(40,116)	$	2,702	$	(67,651)

Six Months Ended June 30, 2017
Balance at beginning of period	$	(30,237)	$	(59,958)	$	2,184	$	(88,011)
Other comprehensive income		—		19,842		518		20,360
Balance at end of period	$	(30,237)	$	(40,116)	$	2,702	$	(67,651)