CONDENSED PARENT COMPANY INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets
Other assets	$ 177,849	$ 186,775
Total Assets	14,724,388	13,798,662	$ 13,326,369
Liabilities and shareholders' equity:
Total liabilities	13,000,505	12,143,218
Shareholders' equity	1,723,883	1,655,444	1,606,059	$ 1,513,130
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	14,724,388	13,798,662
Condensed Statements of Income [Abstract]
Income before income taxes	196,444	186,739	167,402
Income tax benefit	(63,716)	(59,248)	(50,652)
Net Income	132,728	127,491	116,750
Operating activities:
Net income	132,728	127,491	116,750
Net cash provided by operating activities	143,496	133,306	142,129
Investing activities:
Net cash (used in) provided by investing activities	(941,237)	(627,004)	(459,359)
Financing activities:
Cash dividends	(42,310)	(33,368)	(23,983)
Redemption of junior subordinated debt securities	(10,310)		(8,248)
Advance of long-term debt	500,000		8,000
Repayment of long-term debt	(39,775)	(8,373)	(8,066)
Common stock transactions, net	2,773	10,441	11,583
Net cash (used in) provided by financing activities	822,737	334,417	146,057
(Decrease) increase in Cash and Cash Equivalents	24,996	(159,281)	(171,173)
Cash and Cash Equivalents at Beginning of Year	197,969	357,250	528,423
Cash and Cash Equivalents at End of Year	222,965	197,969	357,250
BancorpSouth, Inc. (Parent Company Only) [Member]
Assets
Cash on deposit with subsidiary bank	166,593	86,767
Investment in subsidiaries	1,567,834	1,623,640
Other assets	4,846	11,237
Total Assets	1,739,273	1,721,644
Liabilities and shareholders' equity:
Total liabilities	15,390	66,200
Shareholders' equity	1,723,883	1,655,444
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	1,739,273	1,721,644
Condensed Statements of Income [Abstract]
Dividends from subsidiaries	192,000	100,000	60,000
Other operating income	(404)	1,075	585
Total income	191,596	101,075	60,585
Operating expenses	7,547	8,419	6,867
Income before income taxes	184,049	92,656	53,718
Income tax benefit	3,051	2,818	2,420
Income (loss) before equity in undistributed earnings of subsidiaries	187,100	95,474	56,138
Equity in undistributed (distributed) earnings of subsidiaries	(54,372)	32,017	60,612
Net Income	132,728	127,491	116,750
Operating activities:
Net income	132,728	127,491	116,750
Adjustments to reconcile net income to net cash provided by operating activities	60,882	(32,255)	(61,862)
Net cash provided by operating activities	193,610	95,236	54,888
Financing activities:
Cash dividends	(42,310)	(33,368)	(23,983)
Redemption of junior subordinated debt securities	(10,310)		(8,248)
Advance of long-term debt			8,000
Repayment of long-term debt	(39,775)	(8,373)	(8,066)
Common stock transactions, net	(21,389)	(59,998)	13,928
Net cash (used in) provided by financing activities	(113,784)	(101,739)	(18,369)
(Decrease) increase in Cash and Cash Equivalents	79,826	(6,503)	36,519
Cash and Cash Equivalents at Beginning of Year	86,767	93,270	56,751
Cash and Cash Equivalents at End of Year	$ 166,593	$ 86,767	$ 93,270