Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Allowance for loan losses	$ 18,228	$ 16,458
Excess book over tax SERP retirement plan cost	2,553	2,378
Deferred compensation	128	138
State net operating loss carryforwards	961	62
Accruals, book versus tax	1,403	329
Pension liability adjustments	1,396	7,220
Foreclosed real estate	6,813	1,402
Basis differences in assets acquired in FDIC transactions	1,058	771
Nonqualified stock options	554	277
Nonaccrual loan interest	420	744
All other	732	663
Gross deferred tax assets	34,246	30,442
Less: Valuation allowance	(112)	(81)
Net deferred tax assets	34,134	30,361
Deferred tax liabilities:
Loan fees	(1,427)	(1,217)
Excess tax over book pension cost	(451)	(219)
Depreciable basis of fixed assets	(2,308)	(2,372)
Amortizable basis of intangible assets	(9,119)	(8,334)
Unrealized gain on securities available for sale	(1,283)	(1,520)
FHLB stock dividends	(437)	(437)
All other	(124)	(198)
Gross deferred tax liabilities	(15,149)	(14,297)
Net deferred tax asset (liability) - included in other assets	$ 18,985	$ 16,064