Restructuring Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			12 Months Ended		9 Months Ended		9 Months Ended			12 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 2012 Restructuring Program [Member]	Dec. 31, 2011 2011 Restructuring Program [Member]	Sep. 30, 2012 2011 Restructuring Program [Member]	Sep. 30, 2012 Prior Restructuring Programs [Member]	Dec. 31, 2011 Prior Restructuring Programs [Member]	Sep. 30, 2012 Facility Related [Member] 2012 Restructuring Program [Member] Company Owned Brokerage Services [Member]	Sep. 30, 2012 Facility Related [Member] 2012 Restructuring Program [Member] Relocation Services [Member]	Sep. 30, 2012 Facility Related [Member] 2012 Restructuring Program [Member] Title and Settlement Services [Member]	Dec. 31, 2011 Facility Related [Member] 2011 Restructuring Program [Member] Company Owned Brokerage Services [Member]	Dec. 31, 2011 Facility Related [Member] 2011 Restructuring Program [Member] Title and Settlement Services [Member]	Sep. 30, 2012 Personnel Related [Member] 2012 Restructuring Program [Member] Company Owned Brokerage Services [Member]	Dec. 31, 2011 Personnel Related [Member] 2011 Restructuring Program [Member] Company Owned Brokerage Services [Member]	Dec. 31, 2011 Personnel Related [Member] 2011 Restructuring Program [Member] Relocation Services [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges					$ 11
Restructuring costs	2	3	7	8		11				3	1	1	5	1	2	4	1
Restructuring accruals					3		1	11	17
Restructuring reserve utilitzed								$ 6