Acquisition - Narrative (Details) - MBT $ in Thousands, shares in Millions		12 Months Ended
	Sep. 01, 2019 USD ($) bank_branch shares	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Percentage of interest acquired	100.00%
Number of banking centers acquired | bank_branch	20
Less: Common stock issued	$ 229,900
Other intangible assets	16,527
Operating revenue		$ 19,700
Non-recurring expenses		$ 19,700
Core deposit intangibles acquired
Business Acquisition [Line Items]
Other intangible assets	$ 16,527
Acquired intangible asset, expected useful life	10 years
Common Stock
Business Acquisition [Line Items]
Number of shares of common stock	0.275
Stock issued as a part of acquisition (in shares) | shares	6.4