Goodwill and Core Deposit Intangibles (Tables)

9 Months Ended

Sep. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table presents a rollforward of goodwill from the beginning of the year to goodwill as of the dates indicated:

	September 30, 2019		December 31, 2018
Net carrying value at beginning of the period	$	546.7	$	444.7
Additions to provisional goodwill from acquisitions	75.9		102.0
Net carrying value at end of period	$	622.6	$	546.7

Schedule of Core Deposit Intangibles

The following table presents Core deposit intangibles (“CDI”) as of the dates indicated:

	September 30, 2019			December 31, 2018
Gross CDI, at beginning of the period	$	89.7		$	74.0
Established through acquisitions or provisional adjustments	16.6			15.7
Reductions due to sale of accounts	(0.3		)	—
Accumulated amortization	(41.0		)	(32.8		)
Net CDI, end of period	$	65.0		$	56.9

Schedule of Future Amortization Expense

The following table provides the estimated future CDI amortization expense:

Years Ending December 31,
2019 remaining	$	2.9
2020	10.9
2021	9.9
2022	9.0
2023	8.2
Thereafter	24.1
Total	$	65.0