Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in dollars per share)	$ 0.42	[1]	$ 0.41	[2]
Income taxes	$ 181,475	[1]	$ 193,046	[2]
Exercise of stock options, excess tax benefits	47,053	[3]	48,198
Additional Paid-in Capital [Member]
Exercise of stock options, excess tax benefits			15,679
Accounting Standards Update 2016-09 [Member]
Income taxes	$ 14,000
Accounting Standards Update 2016-09 [Member] | Additional Paid-in Capital [Member]
Exercise of stock options, excess tax benefits			$ 16,000

[1] Due to the adoption of ASU 2016-09, certain balances related to excess tax benefits from stock compensation were adjusted prospectively as described in Note 2—New Accounting Standards.

[2] Certain prior year balances were adjusted to give effect to discontinued operations as described in Note 5—Discontinued Operations.

[3] Due to the prospective adoption of ASU 2016-09, the excess tax benefits from stock option exercises of $14 million at September 30, 2016 were recorded in income taxes on the Condensed Statement of Operations rather than additional paid-in-capital on the Condensed Balance Sheets. The 2015 balance of $16 million, under the previous guidance, remains in additional paid-in-capital. See further discussion at Note 2—New Accounting Standards.