Pending Acquisition of Independence Bank (Details) (USD $)				9 Months Ended	0 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014 Independence Bank item	Oct. 21, 2014 Independence Bank Merger agreement	Oct. 21, 2014 Independence Bank Merger agreement Minimum	Oct. 21, 2014 Independence Bank Merger agreement Maximum
Pending Acquisition of Independence Bank
Total assets	$ 2,034,248,000	$ 1,714,187,000	$ 1,569,020,000	$ 426,200,000
Gross loans	1,547,911,000	1,243,252,000	1,142,015,000	341,100,000
Total deposits	1,543,466,000	1,306,286,000	1,284,134,000	358,300,000
Number of branches				6
Consideration paid					71,500,000
Stock price of the acquired entity (in dollars per share)					$ 14.73	$ 13.365	$ 16.335
Cash consideration					7,200,000
Stock issued as part of the acquisition consideration					$ 64,300,000
Ownership interest (as a percent)					20.40%
Share price per share in cash that the acquired entity's shareholder will receive for each share of acquiree (in dollars per share)					$ 13.75
Number of shares of the entity that the acquired entity's shareholder will receive for each share of acquiree					0.9259
Consideration in the form of cash (as a percent)					10.00%
Consideration in the form of stock (as a percent)					90.00%
Period ending on the fifth day prior to the transaction for which average closing price is considered to calculate value of shares to be issued					10 days