Goodwill and Core Deposit Intangibles (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Sep. 30, 2016
Goodwill
Beginning of period	$ 85,291	$ 30,129	$ 30,129
End of the period	85,291		85,291
Core Deposit Intangibles RollForward
Beginning of period	11,562	4,148	4,148
Less amortization	(1,206)	(444)	(847)
End of period	10,356		11,562
Expected future amortization expense
Finite-Lived Intangible Assets, Net, Total	11,562	$ 4,148	4,148	$ 10,356
Core deposit intangibles
Core Deposit Intangibles RollForward
End of period	10,356
Expected future amortization expense
2016				381
2017				1,472
2018				1,196
2019				1,080
2020				992
Thereafter				5,235
Finite-Lived Intangible Assets, Net, Total	$ 10,356			$ 10,356
Core deposit intangibles | Minimum
Core Deposit Intangibles RollForward
Finite-Lived Intangible Asset, Useful Life	6 years
Core deposit intangibles | Maximum
Core Deposit Intangibles RollForward
Finite-Lived Intangible Asset, Useful Life	19 years
Patriot Bancshares Inc
Goodwill
Add acquisition			55,162
Core Deposit Intangibles RollForward
Add acquisition			$ 8,261