Parent Company Only - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2009
Assets
Investment securities	$ 4,143,194	$ 3,585,114
Other assets	801,670	719,162
Total assets	28,356,266	28,414,642			$ 15,000,000
Liabilities:
Long-term debt	859,147	931,442
Total liabilities	25,157,124	25,359,291
Stockholders’ Equity:
Preferred stock	300,000	300,000
Common stock	511	509
Additional paid-in capital	1,045,576	1,025,593
Retained earnings	2,435,393	2,263,502
Treasury stock	(220,334)	(115,310)
Accumulated other comprehensive income/(loss)	(362,004)	(418,943)
Total stockholders’ equity	3,199,142	3,055,351	$ 3,209,616	$ 2,871,224
Total liabilities and stockholders’ equity	28,356,266	28,414,642
Texas Capital Bancshares, Inc.
Assets
Cash and cash equivalents	301,672	245,777
Investment securities	18,845	0
Investment in subsidiaries	3,306,095	3,183,767
Other assets	55,949	93,395
Total assets	3,682,561	3,522,939
Liabilities:
Other liabilities	23,695	6,754
Long-term debt	485,191	484,754
Total liabilities	508,886	491,508
Stockholders’ Equity:
Preferred stock	300,000	300,000
Common stock	511	509
Additional paid-in capital	1,045,576	1,025,593
Retained earnings	2,409,926	2,239,582
Treasury stock	(220,334)	(115,310)
Accumulated other comprehensive income/(loss)	(362,004)	(418,943)
Total stockholders’ equity	3,173,675	3,031,431
Total liabilities and stockholders’ equity	$ 3,682,561	$ 3,522,939