6. Goodwill and Other Intangibles

Changes in the carrying amount of goodwill for the periods ended June 30, 2018 and December 31, 2017 by reportable segment are as follows (in thousands):

	Commercial Banking		Institutional Banking			Personal Banking		Healthcare Services		Total
Balances as of January 1, 2018	$	59,419	$	51,332		$	70,116	$	—	$	180,867
Balances as of June 30, 2018	$	59,419	$	51,332		$	70,116	$	—	$	180,867


Balances as of January 1, 2017	$	59,419	$	98,861		$	70,116	$	—	$	228,396
Discontinued assets ─ goodwill and other intangibles, net		—		(47,529	)		—		—		(47,529	)
Balances as of December 31, 2017	$	59,419	$	51,332		$	70,116	$	—	$	180,867

The following table lists the finite-lived intangible assets that continue to be subject to amortization as of June 30, 2018 and December 31, 2017 (in thousands):

	As of June 30, 2018
	Core Deposit Intangible Assets		Customer Relationships		Other Intangible Assets		Total
Gross carrying amount	$	50,059	$	71,342	$	3,254	$	124,655
Accumulated amortization		43,728		60,463		3,254		107,445
Net carrying amount	$	6,331	$	10,879	$	—	$	17,210

	As of December 31, 2017
	Core Deposit Intangible Assets		Customer Relationships		Other Intangible Assets		Total
Gross carrying amount	$	50,059	$	71,342	$	3,254	$	124,655
Accumulated amortization		42,209		58,935		3,254		104,398
Net carrying amount	$	7,850	$	12,407	$	—	$	20,257

The following table has the aggregate amortization expense recognized in each period (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Aggregate amortization expense	$	1,485	$	1,924	$	3,047	$	3,970

The following table lists estimated amortization expense of intangible assets in future periods (in thousands):

For the six months ending December 31, 2018	$	2,666
For the year ending December 31, 2019		4,714
For the year ending December 31, 2020		3,759
For the year ending December 31, 2021		2,755
For the year ending December 31, 2022		1,815
For the year ending December 31, 2023		1,097