Quarterly Condensed Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 35,096	$ 33,180	$ 32,352	$ 32,151	$ 34,385	$ 31,036	$ 32,309	$ 34,024	$ 132,779	$ 131,754	$ 153,289
Interest expense	3,017	3,174	3,072	3,106	3,569	3,592	3,567	3,658	12,369	14,386	18,137
Net interest income	32,079	30,006	29,280	29,045	30,816	27,444	28,742	30,366	120,410	117,368	135,152
Provision for portfolio loan losses	543	599	2,150	1,580	1,968	66	1,348	1,027	4,872	4,409	(642)
Provision (provision reversal) for PCI loan losses	(917)	(227)	0	(3,270)	126	(1,877)	(470)	3,304	(4,414)	1,083	4,974
Net interest income after provision for loan losses	32,453	29,634	27,130	30,735	28,722	29,255	27,864	26,035	119,952	111,876	130,820
Noninterest income	6,557	4,729	5,806	3,583	4,852	4,452	3,405	3,922	20,675	16,631	9,899
Noninterest expense	22,886	19,932	19,458	19,950	24,795	21,121	20,445	21,102	82,226	87,463	90,639
Income before income tax expense	16,124	14,431	13,478	14,368	8,779	12,586	10,824	8,855	58,401	41,044	50,080
Income tax expense	5,445	4,722	4,762	5,022	2,812	4,388	3,664	3,007	19,951	13,871	16,976
Net income	$ 10,679	$ 9,709	$ 8,716	$ 9,346	$ 5,967	$ 8,198	$ 7,160	$ 5,848	$ 38,450	$ 27,173	$ 33,104
Earnings per common share:
Basic (usd per share)	$ 0.53	$ 0.49	$ 0.44	$ 0.47	$ 0.30	$ 0.41	$ 0.36	$ 0.30	$ 1.92	$ 1.38	$ 1.78
Diluted (usd per share)	$ 0.52	$ 0.48	$ 0.43	$ 0.46	$ 0.30	$ 0.41	$ 0.36	$ 0.30	$ 1.89	$ 1.35	$ 1.73