Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Held to maturity, fair value	$ 10,325.4	$ 14,267.0
Total loans and leases, unearned income	$ 13.1	$ 13.2
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 1.6667	$ 1.6667
Common stock, authorized (in shares)	560,000,000	560,000,000
Common stock, outstanding (in shares)	214,890,746	219,012,050
Treasury stock (in shares)	30,280,778	26,159,474
Series C Preferred Stock
Preferred stock, outstanding (in shares)	16,000	16,000
Series D Preferred Stock
Preferred stock, outstanding (in shares)	5,000	5,000