Goodwill and Other Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Components of other intangible assets and related amortization
Aggregate amortization expense	$ 16,551	$ 2,728	$ 1,417
Core deposit intangibles [Member]
Components of other intangible assets and related amortization
Aggregate amortization expense	14,474	2,491	1,114
Credit card and trust relationships [Member]
Components of other intangible assets and related amortization
Aggregate amortization expense	1,908
Value of insurance business acquired [Member]
Components of other intangible assets and related amortization
Aggregate amortization expense	169	213	255
Non-compete agreements [Member]
Components of other intangible assets and related amortization
Aggregate amortization expense		14	28
Trade name [Member]
Components of other intangible assets and related amortization
Aggregate amortization expense		$ 10	$ 20