Unaudited Consolidated Statements of Financial Condition (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Investments:
Amortized cost of trading securities	$ 874	$ 1,306
Amortized cost of investment securities available-for-sale	3,529,671	3,661,146
Fair value of held to maturity securities	858,226	675,721
Loans:
Allowance for loan and lease losses	34,229	31,430
Allowance for covered loan and lease losses	53,036	49,286
Stockholders' equity:
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock liquidation value	25	25
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	47,808,284	47,807,734
Common stock, shares outstanding	44,009,380	46,348,667
Treasury stock at cost, shares	3,798,904	1,459,067
Tax effect on accumulated other comprehensive income (loss)	$ 2,799	$ 2,107
Series A Preferred Stock
Stockholders' equity:
Preferred stock, shares issued	1,340,000	1,340,000
Preferred stock, shares outstanding	1,340,000	1,340,000
Series B Preferred Stock
Stockholders' equity:
Preferred stock, shares issued	1,380,000	1,380,000
Preferred stock, shares outstanding	1,380,000	1,380,000