Fair Value Measurements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Impairment charges	$ 484,000,000	$ 52,000,000	$ 0
Assets:
Investments		80,000,000
Foreign currency hedges	13,000,000	6,000,000
Total Assets	13,000,000	86,000,000
Liabilities:
Deferred compensation	312,000,000	307,000,000
Foreign currency hedges		2,000,000
Total Liabilities	312,000,000	309,000,000
Proceeds from liquidation of investments	79,000,000
Level 1 [Member]
Assets:
Investments		80,000,000
Foreign currency hedges	0	0
Total Assets	0	80,000,000
Liabilities:
Deferred compensation	0	0
Foreign currency hedges		0
Total Liabilities	0	0
Level 2 [Member]
Assets:
Investments		0
Foreign currency hedges	13,000,000	6,000,000
Total Assets	13,000,000	6,000,000
Liabilities:
Deferred compensation	312,000,000	307,000,000
Foreign currency hedges		2,000,000
Total Liabilities	312,000,000	309,000,000
Level 3 [Member]
Assets:
Investments		0
Foreign currency hedges	0	0
Total Assets	0	0
Liabilities:
Deferred compensation	0	0
Foreign currency hedges		0
Total Liabilities	$ 0	$ 0