Segment Reporting - Schedule of Financial Information with Respect to Company's Reportable Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net interest income	$ 116,185	$ 114,405	$ 113,524
Provision for loan losses	11,486	31,089	32,729
Noninterest income	46,549	57,874	52,807
Noninterest expense:
Salaries and employee benefits	56,670	53,122	40,210
Equipment and occupancy expenses	12,286	13,208	11,390
Data processing and telecommunications expenses	11,539	10,683	10,315
Other expenses	41,450	42,457
Total noninterest expense	121,945	119,470	101,953
Income before income tax expense	29,303	21,720	31,649
Applicable income tax benefit/(expense)	9,285	7,285	10,556
Net income	20,018	14,435	21,093
Less preferred stock dividends	1,738	3,577	3,241
Net income available to common shareholders	18,280	10,858	17,852
Total assets	3,667,649	3,019,052
Stockholders' equity	316,699	279,017	293,770
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	112,302	113,347
Provision for loan losses	11,486	31,089
Noninterest income	27,419	44,885
Noninterest expense:
Salaries and employee benefits	44,155	45,456
Equipment and occupancy expenses	11,655	12,726
Data processing and telecommunications expenses	10,966	10,341
Other expenses	37,064	41,056
Total noninterest expense	103,840	109,579
Income before income tax expense	24,395	17,564
Applicable income tax benefit/(expense)	7,567	5,831
Net income	16,828	11,733
Less preferred stock dividends	1,738	3,577
Net income available to common shareholders	15,090	8,156
Total assets	3,545,222	2,938,519
Stockholders' equity	314,594	278,901
Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	3,883	1,058
Noninterest income	19,130	12,989
Noninterest expense:
Salaries and employee benefits	12,515	7,666
Equipment and occupancy expenses	631	482
Data processing and telecommunications expenses	573	342
Other expenses	4,386	1,401
Total noninterest expense	18,105	9,891
Income before income tax expense	4,908	4,156
Applicable income tax benefit/(expense)	1,718	1,454
Net income	3,190	2,702
Net income available to common shareholders	3,190	2,702
Total assets	122,427	80,533
Stockholders' equity	$ 2,105	$ 116