Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Allowance for loan and lease losses	$ 31,698	$ 33,313
Operating lease liabilities	11,127	0
Deferred compensation	7,447	6,251
Employee benefits	6,646	5,652
Acquisition fair market value adjustments	5,480	6,380
Net operating loss carryforwards	2,209	2,525
Available-for-sale debt securities	0	2,244
Other	3,891	3,841
Total gross deferred tax assets	68,498	60,206
Deferred tax liabilities
Intangibles	(16,469)	(12,667)
Depreciation of premises and equipment	(13,987)	(10,776)
Available-for-sale debt securities	(13,652)	0
Deferred Tax Liabilities Operating Lease ROU Assets	(10,506)	0
Deferred loan costs	(7,311)	(6,436)
FHLB stock dividends	(1,486)	(2,722)
Other	(3,050)	(4,041)
Total gross deferred tax liabilities	(66,461)	(36,642)
Net deferred tax asset	$ 2,037	$ 23,564