Noncovered Loans (Analysis of Loan Portfolio by Major Types of Loans) (Details) (USD $) In Thousands	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009
Commercial business	$ 836,745		$ 795,369
Total Real Estate	894,365		843,712
Total real estate construction	82,254		98,146
Consumer	177,564		182,017
Less: deferred loan fees	(3,454)		(3,490)
Loans, excluding covered loans, net of deferred loan fees of ($3,454) and ($3,490), respectively	1,987,474		1,915,754
Less: Allowance for loan and lease losses	(54,057)	(55,315)	(60,993)	(59,748)	(56,981)	(53,478)
Loans, excluding covered loans, net	1,933,417		1,854,761
Loans held for sale	655		754
One-to-Four Family Residential [Member]
One-to-four family residential	51,077		49,383
One-to-four family residential	52,368		67,961
Commercial and Five or More Family Residential Properties [Member]
Commercial and five or more family residential properties	843,288		794,329
Commercial and five or more family residential properties	$ 29,886		$ 30,185