Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table presents changes in the carrying amount of goodwill:

	For the Year Ended December 31,
(In thousands)	2018		2017		2016
Beginning of year	$	147,578	$	64,649	$	25,211
Changes from business combinations	57,175		82,929		39,438
Total	$	204,753	$	147,578	$	64,649

Acquired intangible assets consist of core deposit intangibles

The change in balance for CDI is as follows:

	For the Year Ended December 31,
(In thousands)	2018			2017			2016
Beginning of year	$	18,937		$	14,572		$	8,594
Acquired CDI	10,170			7,726			8,464
Amortization expense	(4,300		)	(3,361		)	(2,486		)
End of year	$	24,807		$	18,937		$	14,572
(In months)
Remaining average amortization period for CDI	58			63			64

Gross Carrying Amount and Accumulated Amortization of Intangible Asset

The gross carrying amount and accumulated amortization of the Company's CDI subject to amortization as of:

	December 31, 2018					December 31, 2017
(In thousands)	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
Deposit base	$	36,691	$	(11,884	)	$	26,522	$	(7,585	)