Acquisitions- Estimated Fair Values of Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Aug. 12, 2011 First National Bank of Olathe [Member]	Jan. 07, 2011 Legacy [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 73,478	$ 8,926
Securities available for sale				37,932	9,569
Other investments				4,563	1,969
Portfolio loans				171,452	73,214
Other real estate				39,124	8,612
FDIC receivable				49,218
FDIC loss share receivable				101,220	25,220
Goodwill	30,334	30,334	2,064	26,712	1,558
Core deposit intangible				7,905	833
Other assets				4,609	466
Total deposits				(508,941)	(113,620)
Federal Home Loan Bank Advances				(1,699)	(16,256)
Other liabilities				$ (5,573)	$ (491)