Restructuring, Impairments and Other Charges (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 15	$ 6	$ 11
Number of sales offices closed	4
Restructuring Reserve, Accrual Adjustment	$ (2)	(2)	(6)
Cash payments	(9)	(10)	(6)
Loss on contract termination	7	14
Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Loss on sale of business			(20)
Net proceeds from business sold			1
Net Assets			11
Foreign currency translation adjustments			6
Indemnification liability			4
Non-cash impairment charges			7
Hotel Group [Member]
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges		7	8
Initially Recorded Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	12
Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	11	5	6
Restructuring Reserve, Accrual Adjustment	0	0	0
Cash payments	(8)	(8)	(6)
Personnel-Related [Member] | Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring			4
Personnel-Related [Member] | Hotel Group [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring			2
Facility-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	2	0	0
Restructuring Reserve, Accrual Adjustment	0	0	0
Cash payments	(1)	(2)	0
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		0	1
Restructuring Reserve, Accrual Adjustment		(1)	(1)
Cash payments		0	0
Restructuring Plan 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	15
Restructuring reserve, non-cash	2
Cash payments	(5)
Remaining liability	8
Restructuring Plan 2016 [Member] | Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	5
Restructuring Plan 2016 [Member] | Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment	(1)
Restructuring Plan 2016 [Member] | Personnel-Related [Member] | Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	5
Restructuring Plan 2016 [Member] | Facility-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	2
Restructuring Plan 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		6
Restructuring reserve, non-cash		1
Cash payments	(3)	(2)
Restructuring Plan 2015 [Member] | Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		2
Restructuring Plan 2015 [Member] | Initially Recorded Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		7
Restructuring Plan 2015 [Member] | Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		5
Restructuring Reserve, Accrual Adjustment	(2)
Restructuring Plan 2015 [Member] | Personnel-Related [Member] | Destination Network [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		1
Restructuring Plan 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, non-cash			5
Restructuring Reserve, Accrual Adjustment		1
Cash payments		$ (6)
Restructuring Plan 2014 [Member] | Personnel-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring			6
Restructuring Plan 2014 [Member] | Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring			$ 1
Restructuring Plans, Additional [Member]
Restructuring Cost and Reserve [Line Items]
Cash payments	(1)
Remaining liability	1
Operating Expense [Member]
Restructuring Cost and Reserve [Line Items]
Foreign exchange loss	$ 24