Parent Company only Condensed Financial Information - Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed statements of income
Interest expense	$ (2,318)	$ (2,159)	$ (1,816)	$ (1,529)	$ (1,708)	$ (1,634)	$ (1,174)	$ (871)	$ (7,822)	$ (5,387)	$ (3,211)
Income before income taxes	18,370	17,354	884	12,047	13,977	13,832	12,018	10,472	48,655	50,299	43,969
Equity in undistributed net income of subsidiary bank:
Income tax benefit	(5,138)	(4,979)	31	(3,238)	(12,719)	(5,249)	(4,569)	(3,934)	(13,324)	(26,471)	(16,588)
Net income	$ 13,232	$ 12,375	$ 915	$ 8,809	$ 1,258	$ 8,583	$ 7,449	$ 6,538	35,331	23,828	27,381
Dividends and discount accretion on preferred stock											(1,512)
Net income available to common shareholders									35,331	23,828	25,869
HCC (Parent)
Condensed statements of income
Dividend from subsidiary bank									17,000	16,000	18,000
Other Income										114
Interest expense									(2,315)	(1,394)	(11)
Other expenses									(3,030)	(2,270)	(2,568)
Income before income taxes									11,655	12,450	15,421
Equity in undistributed net income of subsidiary bank:
Undistributed net income of subsidiary bank									22,161	10,078	10,897
Income tax benefit									1,515	1,300	1,063
Net income									35,331	23,828	27,381
Dividends and discount accretion on preferred stock											(1,512)
Net income available to common shareholders									$ 35,331	$ 23,828	$ 25,869