Loans And Allowance For Loan Losses (Southwest's Loan Classifications) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	$ 1,254,476	$ 1,353,028
Less: Allowance for loan losses	(36,607)	(46,494)
Total loans, net, Noncovered	1,217,869	1,306,534
Loans receivable, Covered	16,427	25,707
Less: Allowance for loan losses	(56)	(224)
Net covered loans receivable	16,371	25,483
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	254,087	240,498
Loans receivable, Covered	971	2,037
Commercial Real Estate [Member] | Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	740,997	870,975
Loans receivable, Covered	11,282	18,298
Commercial Real Estate [Member] | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	143,650	130,753
Loans receivable, Covered	198	382
One-To-Four Family Residential [Member] | Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	80,058	70,954
Loans receivable, Covered	3,930	4,881
One-To-Four Family Residential [Member] | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	4,646	3,656
Guaranteed Student Loans [Member] | Installment And Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	4,394	4,680
Other [Member] | Installment And Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, Noncovered	26,644	31,512
Loans receivable, Covered	$ 46	$ 109