Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets-Accumulated Amortization of Intangible Assets Schedule (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 96,561	$ 101,873	$ 101,873
Finite-Lived Intangible Assets, Accumulated Amortization	(22,608)	(19,118)	(16,426)
Finite-Lived Intangible Assets, Net	73,953	82,755	85,447
Core Deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	82,323	87,533	87,533
Finite-Lived Intangible Assets, Accumulated Amortization	(17,712)	(16,065)	(14,325)
Finite-Lived Intangible Assets, Net	64,611	71,468	73,208
Noncompete Agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		102	102
Finite-Lived Intangible Assets, Accumulated Amortization		(102)	(96)
Finite-Lived Intangible Assets, Net		0	6
Lease Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	238	238	238
Finite-Lived Intangible Assets, Accumulated Amortization	(167)	(140)	(131)
Finite-Lived Intangible Assets, Net	71	98	107
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	14,000	14,000	14,000
Finite-Lived Intangible Assets, Accumulated Amortization	(4,729)	(2,811)	(1,874)
Finite-Lived Intangible Assets, Net	$ 9,271	$ 11,189	$ 12,126