Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Securities held to maturity, fair value	$ 1,038,434	$ 959,414
Unearned income on loans	$ 45,019	$ 42,183
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	127,240,016	114,902,454
Treasury stock, shares	215,117	155,369