Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 48,612	$ 38,667
Provision for loan and lease losses	6,331	637
Total noninterest income	18,727	25,966
Total noninterest expense	52,415	46,245
INCOME BEFORE INCOME TAXES	8,593	17,751
Segment Assets	5,747,102	4,900,558	5,923,716
Average Loans	3,571,127	2,876,960
Community and Other Banking
Segment Reporting Information [Line Items]
Net interest income	47,855	38,324
Provision for loan and lease losses	6,331	637
Total noninterest income	11,403	12,891
Total noninterest expense	42,214	34,018
INCOME BEFORE INCOME TAXES	10,713	16,560
Segment Assets	5,669,512	4,787,006
Average Loans	3,528,356	2,784,785
Retail Mortgage Banking
Segment Reporting Information [Line Items]
Net interest income	757	343
Provision for loan and lease losses	0	0
Total noninterest income	7,324	13,075
Total noninterest expense	10,201	12,227
INCOME BEFORE INCOME TAXES	(2,120)	1,191
Segment Assets	77,590	113,552
Average Loans	$ 42,771	$ 92,175