Changes in Consolidated Stockholders' Equity (Parenthetical) (Parentheticals) - shares	3 Months Ended			12 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Common shares issued from treasury stock for stock-based compensation (in shares)				4,164,134	2,931,595	10,106,542
Common shares repurchased (in shares)	19,600,000	18,100,000	23,700,000	0	25,841,608	41,762,325