Consolidated Statement of Changes in Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock option exercises/deferred stock unit conversions, shares	1,319,786	206,336	148,203
Non-vested stock awards, shares	13,040	16,850	22,360
Non-vested stock units, shares	24,970	32,280	33,940
Issuance of preferred stock, shares	6,000,000
Purchase of treasury stock, shares	2,245,572	7,960	37,464
Common stock issued/sold to the 401 (k) stock purchase plan, shares			22,680
Cash dividends declared on preferred stock, per share	$ 1.12
Cash dividends - common stock, per share	$ 1.98	$ 1.90	$ 1.83