Subsequent Event (Details Textual) - USD ($)	Oct. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Subsequent Event
Total assets		$ 8,764,299,000	$ 8,306,507,000
Subsequent Event
Subsequent Event
Subsequent Event, Description	The Company acquired 100 percent of the outstanding common stock of Cañon Bank Corporation and its wholly-owned subsidiary, Cañon National Bank.
Subsequent Event | Canon National Bank
Subsequent Event
Percentage of Outstanding Common Stock Acquired	100.00%
Business Combination, Consideration Transferred	$ 31,308,000
Number of Shares Issued for Aquisition	554,206
Cash consideration for outstanding shares	$ 16,145,000
Total assets	$ 258,179,000