Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Schedule of Changes in Carrying Amount of Goodwill

The following table shows the changes in the carrying amount of goodwill for the three months ended March 31, 2019 and 2018:

	Three Months Ended
	March 31,
(dollars in thousands)	2019		2018
Balance at beginning of period	$	1,036,258	$	828,051
Acquisition adjustments		—		753
Balance at end of period	$	1,036,258	$	828,804

Schedule of Gross Carrying Amounts and Accumulated Amortization of Other Intangible Assets

The gross carrying amount and accumulated amortization of other intangible assets at March 31, 2019 and December 31, 2018 were as follows:

	Gross		Accumulated			Net
	Carrying		Amortization			Carrying
(dollars in thousands)	Amount		and Impairment			Amount
March 31, 2019
Core deposit	$	119,051	$	(51,588	)	$	67,463
Customer trust relationships		16,547		(11,466	)		5,081
Total intangible assets	$	135,598	$	(63,054	)	$	72,544
December 31, 2018
Core deposit	$	129,100	$	(57,524	)	$	71,576
Customer trust relationships		16,547		(11,107	)		5,440
Total intangible assets	$	145,647	$	(68,631	)	$	77,016

Schedule of Estimated Amortization Expense for Future Years

Estimated amortization expense for future years is as follows:

(dollars in thousands)
2019 remaining	$	12,439
2020		14,091
2021		11,336
2022		9,014
2023		7,053
Thereafter		18,611
Total	$	72,544