Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	6 Months Ended
Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Stock issued for employee stock purchase plan, shares (in shares)	39,782		26,002
Stock issued for compensation plans, shares (in shares)	212,470	115,010	244,276
Cash dividends per share (in dollars per share)	$ 0.30	$ 0.25	$ 0.25
Hardeman County Investment Company, Inc.
Stock issued for acquisition (in shares)			1,599,940
OKSB Merger
Stock issued for acquisition (in shares)		14,488,604
First Texas Merger
Stock issued for acquisition (in shares)		12,999,840

Aggregate dividends declared during the period for each share of common stock outstanding.

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