FAIR VALUE MEASUREMENTS - Additional Information on Non-Recurring Basis (Detail) - USD ($) $ in Thousands		Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		$ 4,400
Loans held for sale	[1]	28,213		$ 56,458
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value		0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value		0		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value		43,497		37,758
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		7,595		4,110
Other real estate owned		5,500		21,336
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		0		0
Other real estate owned		0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		1,460		2,813
Other real estate owned		0		10,513
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		6,135		1,297
Other real estate owned		5,500		10,823
SBA-Guaranteed Loan Servicing [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value		4,894	$ 5,062	5,058	$ 5,299	$ 5,339	$ 0
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale				36,432
Loan servicing rights, fair value		4,894		5,058
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale				0
Loan servicing rights, fair value		0		0
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale				0
Loan servicing rights, fair value		0		0
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale				36,432
Loan servicing rights, fair value		$ 4,894		$ 5,058

[1] Amount represents loans for which we have elected the fair value option. See Note 18.