Consolidated Statements Of Condition (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Held-to-maturity securities	$ 942,666	$ 878,111	$ 0
Preferred stock, no par value (usd per share)
Preferred stock, 20,000,000 shares authorized	20,000,000	20,000,000	20,000,000
Common stock, no par value (usd per share)
Common stock, $1.00 stated value (usd per share)	$ 1.00	$ 1.00	$ 1.00
Common stock, 100,000,000 shares authorized	100,000,000	100,000,000	100,000,000
Common stock, shares issued	51,811,204	48,468,894	48,422,294
Treasury stock, shares	96,521	85,615	85,424
Series C Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 1,000	$ 1,000	$ 1,000
Preferred stock, shares outstanding	126,257	126,287	126,312
Series D Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 25	$ 25	$ 25
Preferred stock, shares outstanding	5,000,000	5,000,000	5,000,000