Parent Company Only (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2014	Sep. 21, 2012
Assets
Cash and cash equivalents	$ 4,425,583	$ 3,080,065	$ 2,905,591	$ 2,839,352
Loans held for investment (net of unearned income)	16,476,413	16,690,550
Other assets	740,051	626,614
Total assets	32,548,069	28,257,767
Liabilities and Stockholders’ Equity
Subordinated notes, net	282,129	281,767
Trust preferred subordinated debentures	113,406	113,406			$ 175,000	$ 111,000
Total liabilities	29,715,811	25,757,373
Preferred stock	150,000	150,000
Common stock	503	502
Additional paid-in capital	978,205	967,890
Retained earnings	1,694,608	1,381,492
Treasury stock	(8)	(8)
Accumulated other comprehensive income	8,950	518
Total stockholders’ equity	2,832,258	2,500,394	2,202,721	2,009,557
Total liabilities and stockholders’ equity	32,548,069	28,257,767
Texas Capital Bancshares, Inc.
Assets
Cash and cash equivalents	71,462	89,561	$ 144,635	$ 220,499
Loans held for investment (net of unearned income)	10,500	7,500
Investment in subsidiaries	2,878,330	2,534,341
Other assets	88,639	87,451
Total assets	3,048,931	2,718,853
Liabilities and Stockholders’ Equity
Other liabilities	1,768	1,471
Subordinated notes, net	108,715	108,614
Trust preferred subordinated debentures	113,406	113,406
Total liabilities	223,889	223,491
Preferred stock	150,000	150,000
Common stock	503	502
Additional paid-in capital	988,357	978,042
Retained earnings	1,677,240	1,366,308
Treasury stock	(8)	(8)
Accumulated other comprehensive income	8,950	518
Total stockholders’ equity	2,825,042	2,495,362
Total liabilities and stockholders’ equity	$ 3,048,931	$ 2,718,853