Loans - Credit risk profile by risk grade of non acquired loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Loans
Total loans	$ 11,375,104	$ 11,226,192
Construction and land development
Loans
Total loans	1,017,261	957,346
Other income producing property
Loans
Total loans	346,554	367,353
Consumer Owner Occupied Loans
Loans
Total loans	2,706,960	2,762,266
Commercial loans | Commercial non-owner occupied
Loans
Total loans	2,323,967	2,398,249
Commercial loans | Commercial owner occupied real estate loan
Loans
Total loans	2,158,701	2,047,933
Commercial loans | Commercial and industrial
Loans
Total loans	1,386,327	1,271,464
Commercial loans | Other loans
Loans
Total loans	13,892	1,601
Consumer | Home equity loans
Loans
Total loans	758,020	778,234
Consumer | Consumer
Loans
Total loans	663,422	641,746
Non-acquired loans
Loans
Total loans	9,252,831	8,621,327
Non-acquired loans | Pass
Loans
Total loans	9,123,097	8,504,898
Non-acquired loans | Special mention
Loans
Total loans	83,830	66,580
Non-acquired loans | Substandard
Loans
Total loans	45,904	49,849
Non-acquired loans | Other income producing property
Loans
Total loans	218,617	214,203
Non-acquired loans | Other income producing property | Pass
Loans
Total loans	213,291	208,598
Non-acquired loans | Other income producing property | Special mention
Loans
Total loans	3,966	4,376
Non-acquired loans | Other income producing property | Substandard
Loans
Total loans	1,360	1,229
Non-acquired loans | Commercial loans
Loans
Total loans	6,062,991	5,522,067
Non-acquired loans | Commercial loans | Pass
Loans
Total loans	5,971,069	5,446,710
Non-acquired loans | Commercial loans | Special mention
Loans
Total loans	69,268	50,470
Non-acquired loans | Commercial loans | Substandard
Loans
Total loans	22,654	24,887
Non-acquired loans | Commercial loans | Construction and land development
Loans
Total loans	968,360	879,724
Non-acquired loans | Commercial loans | Construction and land development | Pass
Loans
Total loans	959,206	871,393
Non-acquired loans | Commercial loans | Construction and land development | Special mention
Loans
Total loans	7,095	5,948
Non-acquired loans | Commercial loans | Construction and land development | Substandard
Loans
Total loans	2,059	2,383
Non-acquired loans | Commercial loans | Commercial non-owner occupied
Loans
Total loans	1,811,138	1,723,640
Non-acquired loans | Commercial loans | Commercial non-owner occupied | Pass
Loans
Total loans	1,787,306	1,714,606
Non-acquired loans | Commercial loans | Commercial non-owner occupied | Special mention
Loans
Total loans	22,410	7,557
Non-acquired loans | Commercial loans | Commercial non-owner occupied | Substandard
Loans
Total loans	1,422	1,477
Non-acquired loans | Commercial loans | Commercial owner occupied real estate loan
Loans
Total loans	1,784,017	1,589,987
Non-acquired loans | Commercial loans | Commercial owner occupied real estate loan | Pass
Loans
Total loans	1,754,801	1,561,594
Non-acquired loans | Commercial loans | Commercial owner occupied real estate loan | Special mention
Loans
Total loans	19,742	16,310
Non-acquired loans | Commercial loans | Commercial owner occupied real estate loan | Substandard
Loans
Total loans	9,474	12,083
Non-acquired loans | Commercial loans | Commercial and industrial
Loans
Total loans	1,280,859	1,114,513
Non-acquired loans | Commercial loans | Commercial and industrial | Pass
Loans
Total loans	1,256,465	1,090,519
Non-acquired loans | Commercial loans | Commercial and industrial | Special mention
Loans
Total loans	16,055	16,279
Non-acquired loans | Commercial loans | Commercial and industrial | Substandard
Loans
Total loans	8,339	7,715
Non-acquired loans | Commercial loans | Other loans
Loans
Total loans	13,892	1,601
Non-acquired loans | Consumer
Loans
Total loans	3,189,840	3,099,260
Non-acquired loans | Consumer | Pass
Loans
Total loans	3,152,028	3,058,188
Non-acquired loans | Consumer | Special mention
Loans
Total loans	14,562	16,110
Non-acquired loans | Consumer | Substandard
Loans
Total loans	23,250	24,962
Non-acquired loans | Consumer | Consumer Owner Occupied Loans
Loans
Total loans	2,118,839	2,079,949
Non-acquired loans | Consumer | Consumer Owner Occupied Loans | Pass
Loans
Total loans	2,094,080	2,052,808
Non-acquired loans | Consumer | Consumer Owner Occupied Loans | Special mention
Loans
Total loans	9,585	9,936
Non-acquired loans | Consumer | Consumer Owner Occupied Loans | Substandard
Loans
Total loans	15,174	17,205
Non-acquired loans | Consumer | Home equity loans
Loans
Total loans	518,628	514,242
Non-acquired loans | Consumer | Home equity loans | Pass
Loans
Total loans	508,054	502,305
Non-acquired loans | Consumer | Home equity loans | Special mention
Loans
Total loans	4,490	5,731
Non-acquired loans | Consumer | Home equity loans | Substandard
Loans
Total loans	6,084	6,206
Non-acquired loans | Consumer | Consumer
Loans
Total loans	538,481	503,468
Non-acquired loans | Consumer | Consumer | Pass
Loans
Total loans	536,002	501,474
Non-acquired loans | Consumer | Consumer | Special mention
Loans
Total loans	487	443
Non-acquired loans | Consumer | Consumer | Substandard
Loans
Total loans	1,992	1,551
Non-acquired loans | Consumer | Other loans
Loans
Total loans	13,892	1,601
Non-acquired loans | Consumer | Other loans | Pass
Loans
Total loans	$ 13,892	$ 1,601