Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Jun. 15, 2016	Apr. 05, 2016
Excess tax benefit from stock option exercises, financing activities	[1]	$ 0	$ 15,679
Accounting Standards Update 2016-09 [Member]
Excess tax benefit from stock option exercises, operating activities		$ 14,000
Excess tax benefit from stock option exercises, financing activities			$ 16,000
Senior Notes due June 15, 2016 [Member] | Senior Notes [Member]
Stated interest rate (percent)		6.375%	6.375%	6.375%
Junior Subordinated Debentures due 2056 [Member] | Junior Subordinated Debt [Member]
Stated interest rate (percent)		6.125%	6.125%		6.125%

[1] 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 presented as a component of operating activities in the same manner as other cash flows related to income taxes. The 2015 balance of $16 million, under the previous guidance, remains in the financing activities section. See further discussion at Note 2—New Accounting Standards.