CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Amortized cost	$ 236,018	$ 211,406
Allowance for loan losses	229,919	184,701
Tax benefit for accumulated other comprehensive (loss) income	$ (2,720)	$ (5,364)
Preferred stock, stated value (in dollars per share)	$ 0.20	$ 0.20
Preferred stock shares authorized (in shares)	20,000,000	20,000,000
Common stock par value (in dollars per share)	$ 0.20	$ 0.20
Common stock, shares authorized (in shares)	1,125,000,000.000	1,125,000,000.000
Common stock shares issued (in shares)	442,300,000.0	436,600,000.0
Common stock held in treasury (in shares)	10,400,000	7,700,000
Series A Preferred Stock
Preferred stock, stated value (in dollars per share)	$ 0	$ 50
Preferred stock shares outstanding (in shares)	0	3,300,000
Series B Preferred Stock
Preferred stock, stated value (in dollars per share)	$ 100	$ 100
Preferred stock shares outstanding (in shares)	4,000,000	4,000,000