Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock Southeastern Bank Financial	Common Stock Park Sterling Corporation	Common Stock	Surplus Southeastern Bank Financial	Surplus Park Sterling Corporation	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Southeastern Bank Financial	Park Sterling Corporation	Total
Balance at Dec. 31, 2016			$ 60,576			$ 711,307	$ 370,916	$ (8,211)			$ 1,134,588
Balance (in shares) at Dec. 31, 2016			24,230,392
Increase (Decrease) in Stockholders' Equity
Net income							87,554				87,554
Other comprehensive income (loss), net of tax effects								(2,216)			(2,216)
Comprehensive income											85,338
Cash dividends declared on common stock per share							(38,623)				(38,623)
Employee stock purchases			$ 32			1,023					1,055
Employee stock purchases (in shares)			12,798
Stock options exercised			$ 149			1,816					1,965
Stock options exercised (in shares)			59,480
Restricted stock awards			$ 53			(53)
Restricted stock awards (in shares)			21,628
Stock issued pursuant to restricted stock units			$ 95			(95)
Stock issued pursuant to restricted stock units (in shares)			37,802
Common stock issued for acquisition	$ 12,446	$ 18,701		$ 422,163	$ 669,865				$ 434,609	$ 688,566
Common stock issued for acquisition (in shares)	(4,978,338)	(7,480,343)
Common stock repurchased			$ (153)			(5,359)					(5,512)
Common stock repurchased (in shares)			(61,125)
Share-based compensation expense						6,934					6,934
Balance at Dec. 31, 2017			$ 91,899			1,807,601	419,847	(10,427)			2,308,920
Balance (in shares) at Dec. 31, 2017			36,759,656
Increase (Decrease) in Stockholders' Equity
Net income							178,871				178,871
Other comprehensive income (loss), net of tax effects								(11,507)			(11,507)
Comprehensive income											167,364
Cash dividends declared on common stock per share							(50,557)				(50,557)
AOCI reclassification to retained earnings from adoption of ASU 2018-02							2,947	(2,947)			(2,947)
Employee stock purchases			$ 45			1,286					1,331
Employee stock purchases (in shares)			18,110
Stock options exercised			$ 84			948					1,032
Stock options exercised (in shares)			33,424
Restricted stock awards			$ 10			(10)
Restricted stock awards (in shares)			4,069
Stock issued pursuant to restricted stock units			$ 99			(99)
Stock issued pursuant to restricted stock units (in shares)			39,541
Common stock repurchased - buyback plan			$ (2,500)			(65,904)					(68,404)
Common stock repurchased - buyback plan (in shares)			(1,000,000)
Common stock repurchased			$ (63)			(2,110)					(2,173)
Common stock repurchased (in shares)			(25,251)
Share-based compensation expense						8,783					8,783
Balance at Dec. 31, 2018			$ 89,574			1,750,495	551,108	(24,881)			$ 2,366,296
Balance (in shares) at Dec. 31, 2018			35,829,549								35,829,549
Increase (Decrease) in Stockholders' Equity
Net income							186,483				$ 186,483
Other comprehensive income (loss), net of tax effects								25,898			25,898
Comprehensive income											212,381
Cash dividends declared on common stock per share							(57,696)				(57,696)
Employee stock purchases			$ 53			1,341					1,394
Employee stock purchases (in shares)			21,100
Stock options exercised			$ 92			1,138					1,230
Stock options exercised (in shares)			36,978
Restricted stock awards			$ 15			(15)
Restricted stock awards (in shares)			5,889
Stock issued pursuant to restricted stock units			$ 129			(129)
Stock issued pursuant to restricted stock units (in shares)			51,543
Common stock repurchased - buyback plan			$ (5,413)			(151,532)					(156,945)
Common stock repurchased - buyback plan (in shares)			(2,165,000)
Common stock repurchased			$ (89)			(2,397)					(2,486)
Common stock repurchased (in shares)			(35,674)
Share-based compensation expense						8,839					8,839
Balance at Dec. 31, 2019			$ 84,361			$ 1,607,740	$ 679,895	$ 1,017			$ 2,373,013
Balance (in shares) at Dec. 31, 2019			33,744,385								33,744,385