The name of wholly owned, consolidated subsidiaries.

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The name of wholly owned, equity method subsidiaries.

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The amount of fair value of equity-based compensation awards other than stock and unit options in excess of the recorded intrinsic value.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Amount of the cumulative effect on retained earnings before related income tax effect.

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Amount of the cumulative effect on retained earnings net of related income tax effect.

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Amount of the related income tax effect of a cumulative effect on retained earnings.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)		3 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	Mar. 11, 2019 $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Change in Capital Structure [Abstract]
Number of common stock shares authorized after change in capital structure (in shares) \| shares	30,000,000	30,000,000	30,000,000
Common stock, par value (in dollars per share) \| $ / shares	$ 1	$ 1.00	$ 1.00
Stock split ratio	29
Pro Forma Information [Abstract]
Federal tax rate		21.00%
Change in Accounting Principle [Abstract]
Cumulative-effect adjustment to retained earnings, net		$ 1,300,000
Cumulative-effect adjustment to retained earnings, before tax		1,600,000
Cumulative-effect adjustment to retained earnings, tax		$ 340,000
City Bank [Member] \| Bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		City Bank
Windmark Insurance Agency Inc. [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		Windmark Insurance Agency, Inc.
Ruidoso Retail, Inc. [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		Ruidoso Retail, Inc.
CB Provence, LLC [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		CB Provence, LLC
CBT Brushy Creek, LLC [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		CBT Brushy Creek, LLC
CBT Properties, LLC [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Consolidated Subsidiaries		CBT Properties, LLC
South Plains Financial Capital Trusts (SPFCT) III-V [Member] \| Non-bank Subsidiary [Member]
Subsidiaries Information [Abstract]
Wholly Owned, Equity Method Subsidiaries		South Plains Financial Capital Trusts (SPFCT) III-V
Stock Appreciation Rights (SARs) [Member]
Change in Accounting Principle [Abstract]
Fair value in excess of recorded intrinsic value			$ 1,600,000