Allowance for Loan and Lease Losses (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Movement in allowance for Loan and Lease Losses:                      
Beginning balance       $ 27,970       $ 24,643 $ 27,970 $ 24,643 $ 27,593
Provision (credit) 1,555 (59) 67 743 585 2,049 2,489 1,038 2,306 6,161 8,837
Recoveries on loans and leases                 3,109 5,347 734
Charge-offs on loans and leases                 (4,388) (8,181) (12,521)
Ending Balance $ 28,997       $ 27,970       $ 28,997 $ 27,970 $ 24,643