BUSINESS COMBINATIONS - fair value of the assets purchased, including goodwill, and liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Apr. 07, 2017	Dec. 31, 2016	Jun. 03, 2016	Mar. 11, 2016
Assets:
Loans, net				$ 314,000
Goodwill	$ 101,739		$ 64,649
Liabilities:
Deposits				63,000
Bank shares, Inc [Member] | Measurement Period Adjustments [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks					$ 0
Investment securities					95
Loans, net					(2,112)
Fixed assets					(628)
Core deposit intangibles					0
Goodwill					1,647
Other assets					998
Total assets acquired					0
Liabilities:
Deposits					0
Other liabilities					0
Total liabilities assumed					0
Bank shares, Inc [Member] | Scenario, Previously Reported [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks					28,243
Investment securities					66,912
Loans, net					268,249
Fixed assets					7,801
Core deposit intangibles					3,375
Goodwill					29,985
Other assets					12,879
Total assets acquired					417,444
Liabilities:
Deposits					337,341
Other liabilities					2,492
Total liabilities assumed					339,833
Bank shares, Inc [Member] | Restatement Adjustment [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks					28,243
Investment securities					67,007
Loans, net					266,137
Fixed assets					7,173
Core deposit intangibles					3,375
Goodwill					31,632
Other assets					13,877
Total assets acquired					417,444
Liabilities:
Deposits					337,341
Other liabilities					2,492
Total liabilities assumed					$ 339,833
BMO Harris Bank [Member] | Measurement Period Adjustments [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks				0
Loans, net				0
Fixed assets				0
Core deposit intangibles				(135)
Goodwill				163
Other assets				(28)
Total assets acquired				0
Liabilities:
Deposits				0
Other liabilities				0
Total liabilities assumed				0
BMO Harris Bank [Member] | Scenario, Previously Reported [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks				234,094
Loans, net				62,671
Fixed assets				3,715
Core deposit intangibles				5,223
Goodwill				7,645
Other assets				952
Total assets acquired				314,300
Liabilities:
Deposits				314,248
Other liabilities				52
Total liabilities assumed				314,300
BMO Harris Bank [Member] | Restatement Adjustment [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks				234,094
Loans, net				62,671
Fixed assets				3,715
Core deposit intangibles				5,088
Goodwill				7,808
Other assets				924
Total assets acquired				314,300
Liabilities:
Deposits				314,248
Other liabilities				52
Total liabilities assumed				$ 314,300
Gulf Shore Banc shares Inc [Member] | Scenario, Previously Reported [Member]
Assets:
Cash, interest bearing deposits and time deposits with other banks		$ 55,540
Investment securities		316
Loans, net		250,884
Fixed assets		1,307
Other real estate owned		13
Core deposit intangibles		3,927
Goodwill		37,090
Other assets		8,572
Total assets acquired		357,649
Liabilities:
Deposits		285,350
Other liabilities		1,382
Total liabilities assumed		$ 286,732