Other Intangible Assets

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Other Intangible Assets

Other Intangible Assets

The following table shows the net carrying value of the Corporation's other intangible assets:

	December 31,
(Dollars in thousands)	2016		2015
Core deposit intangible assets	$	40,211	$	26,654
Non-compete intangible assets	—		328
Total other intangible assets	$	40,211	$	26,982

Core Deposit Intangible Assets

The Corporation recorded core deposit intangibles (CDIs) associated with each of its acquisitions. CDIs are amortized on an accelerated basis over their estimated useful lives and have an estimated remaining weighted-average useful life of 8.4 years as of December 31, 2016.

The following table presents the Corporation's carrying amount and accumulated amortization of CDIs:

	December 31,
(Dollars in thousands)	2016		2015
Gross carrying amount	$	59,143	$	40,055
Accumulated amortization	18,932		13,401
Net carrying amount	$	40,211	$	26,654

Amortization expense recognized on CDIs was $5.2 million, $4.1 million and $2.0 million for the years ended December 31, 2016, 2015 and 2014, respectively.

The estimated future amortization expense on CDIs for the next five years is as follows:

(Dollars in thousands)	Estimated amortization expense
2017	$	5,952
2018	5,703
2019	5,441
2020	4,850
2021	4,471

Non-compete Intangible Assets

In conjunction with the acquisition of Lake Michigan on May 31, 2015, the Corporation recorded $0.6 million in non-compete intangible assets with an amortization period of one year. Amortization expense on non-competes for the years ended December 31, 2016 and 2015 was $328 thousand and $248 thousand, respectively.