Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Additional Paid-in Capital [Member]
Award of common shares released from Employee Benefit Trust (in shares)	129,831,000	136,114,000
Shares issued upon vesting of restricted stock unit awards (in shares)	245,111,000	204,110,000
Issuance upon exercise of stock options (in shares)	18,200,000	1,100,000
Treasury Stock [Member] | Shares Purchased to Fund Options Exercised [Member]
Purchases of shares (in shares)	15,300,000	142,315,000
Treasury Stock [Member] | Restricted Stock Awards Repurchased to Satisfy Tax Obligations [Member]
Purchases of shares (in shares)	76,656,000	58,461,000
Retained Earnings [Member]
Cash dividends declared and paid on common shares (in dollars per share)	$ 0.17	$ 0.16
Issuance upon exercise of stock options (in shares)	18,200