Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets
Investment securities, fair value	$ 462,657	$ 346,105
Real estate and other repossessed assets, allowance	32,911	26,208
Interest-bearing deposits:
Interest bearing deposit liabilities measured at fair value	$ 0	$ 27,414
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0.00006	$ 0.00006
Common stock, shares authorized (in shares)	2,500,000,000	2,500,000,000
Common stock, shares issued (in shares)	71,533,354	70,815,563
Common stock, shares outstanding (in shares)	71,533,354	70,815,563
Treasury stock, shares (in shares)	3,380,310	2,607,874