Loans - Summary of Acquired non-credit impaired loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Summary of Loans
Total loans		$ 11,375,104	$ 11,226,192
Unamortized Discounts	$ 160,800
Construction and land development
Summary of Loans
Total loans		1,017,261	957,346
Consumer Owner Occupied Loans
Summary of Loans
Total loans		2,706,960	2,762,266
Other income producing property
Summary of Loans
Total loans		346,554	367,353
Commercial loans | Commercial non-owner occupied
Summary of Loans
Total loans		2,323,967	2,398,249
Commercial loans | Commercial non-owner occupied real estate
Summary of Loans
Total loans		3,341,228	3,355,595
Commercial loans | Commercial owner occupied real estate loan
Summary of Loans
Total loans		2,158,701	2,047,933
Commercial loans | Commercial and industrial
Summary of Loans
Total loans		1,386,327	1,271,464
Commercial loans | Other loans
Summary of Loans
Total loans		13,892	1,601
Consumer | Home equity loans
Summary of Loans
Total loans		758,020	778,234
Consumer | Real estate
Summary of Loans
Total loans		3,464,980	3,540,500
Consumer | Consumer
Summary of Loans
Total loans		663,422	641,746
Acquired non-credit impaired loans
Summary of Loans
Total loans		1,760,427	2,180,281
Unamortized Discounts		20,300	26,900
Acquired non-credit impaired loans | Other income producing property
Summary of Loans
Total loans		95,697	111,006
Acquired non-credit impaired loans | Consumer
Summary of Loans
Total loans			99,690
Acquired non-credit impaired loans | Commercial loans
Summary of Loans
Total loans		985,780	1,294,530
Acquired non-credit impaired loans | Commercial loans | Construction and land development
Summary of Loans
Total loans		33,569	60,391
Acquired non-credit impaired loans | Commercial loans | Commercial non-owner occupied
Summary of Loans
Total loans		447,441	595,367
Acquired non-credit impaired loans | Commercial loans | Commercial non-owner occupied real estate
Summary of Loans
Total loans		481,010	655,758
Acquired non-credit impaired loans | Commercial loans | Commercial owner occupied real estate loan
Summary of Loans
Total loans		307,193	376,187
Acquired non-credit impaired loans | Commercial loans | Commercial and industrial
Summary of Loans
Total loans		101,880	151,579
Acquired non-credit impaired loans | Commercial loans | Other income producing property
Summary of Loans
Total loans		95,697	111,006
Acquired non-credit impaired loans | Consumer
Summary of Loans
Total loans		774,647	885,751
Acquired non-credit impaired loans | Consumer | Consumer Owner Occupied Loans
Summary of Loans
Total loans		496,431	577,284
Acquired non-credit impaired loans | Consumer | Home equity loans
Summary of Loans
Total loans		188,732	208,777
Acquired non-credit impaired loans | Consumer | Real estate
Summary of Loans
Total loans		685,163	786,061
Acquired non-credit impaired loans | Consumer | Consumer
Summary of Loans
Total loans		$ 89,484	$ 99,690