Variable Interest Entities (Details)		1 Months Ended	3 Months Ended								9 Months Ended	12 Months Ended
		Aug. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2017	Dec. 31, 2017 USD ($) Closing	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
ASSETS
Cash			$ 542,000,000				$ 906,000,000					$ 542,000,000	$ 906,000,000	$ 906,000,000	$ 1,259,000,000
Restricted cash			41,000,000				57,000,000					41,000,000	57,000,000
Mortgage loans held for sale			270,000,000				683,000,000					270,000,000	683,000,000
Accounts receivable, net			78,000,000				66,000,000					78,000,000	66,000,000
Servicing advances, net			356,000,000				628,000,000					356,000,000	628,000,000
Property and equipment, net			22,000,000				36,000,000					22,000,000	36,000,000
Other assets			26,000,000				109,000,000					26,000,000	109,000,000
Total assets	[1]		1,811,000,000				3,175,000,000					1,811,000,000	3,175,000,000
LIABILITIES
Accounts payable and accrued expenses			141,000,000				193,000,000					141,000,000	193,000,000
Mortgage warehouse and advance facilities			252,000,000				655,000,000					252,000,000	655,000,000
Other liabilities			47,000,000				157,000,000					47,000,000	157,000,000
Total liabilities	[1]		1,258,000,000				2,052,000,000					1,258,000,000	2,052,000,000
Company Involvement with Variable Interest Entity
Net loss			(31,000,000)	$ (42,000,000)	$ (50,000,000)	$ (71,000,000)	(133,000,000)	$ (21,000,000)	$ (9,000,000)	$ (30,000,000)		$ (194,000,000)	(193,000,000)	(131,000,000)
Variable Interest Entities
Number of asset sale closings | Closing												5
Proceeds from PHH Home Loans asset sales		$ 70,000,000										$ 70,000,000	0	0
Gain on PHH Home Loans asset sales		$ (70,000,000)										(70,000,000)	0	0
Exit and disposal costs												62,000,000	41,000,000	0
Mandatorily redeemable noncontrolling interest			20,000,000				0					$ 20,000,000	0
Notice period of purchase requirement											2 years	2 years
Variable Interest Entity
ASSETS
Cash			33,000,000				67,000,000					$ 33,000,000	67,000,000
Restricted cash			13,000,000				24,000,000					13,000,000	24,000,000
Mortgage loans held for sale			60,000,000				350,000,000					60,000,000	350,000,000
Accounts receivable, net			1,000,000				9,000,000					1,000,000	9,000,000
Servicing advances, net			56,000,000				150,000,000					56,000,000	150,000,000
Property and equipment, net			0				1,000,000					0	1,000,000
Other assets			1,000,000				12,000,000					1,000,000	12,000,000
Total assets			164,000,000				613,000,000					164,000,000	613,000,000
LIABILITIES
Accounts payable and accrued expenses			6,000,000				11,000,000					6,000,000	11,000,000
Mortgage warehouse and advance facilities			72,000,000				399,000,000					72,000,000	399,000,000
Other liabilities			5,000,000				5,000,000					5,000,000	5,000,000
Total liabilities			83,000,000				415,000,000					83,000,000	415,000,000
PHH Home Loans | Variable Interest Entity
ASSETS
Cash			33,000,000				67,000,000					33,000,000	67,000,000
Restricted cash			3,000,000				5,000,000					3,000,000	5,000,000
Mortgage loans held for sale			60,000,000				350,000,000					60,000,000	350,000,000
Accounts receivable, net			1,000,000				9,000,000					1,000,000	9,000,000
Servicing advances, net			0				0					0	0
Property and equipment, net			0				1,000,000					0	1,000,000
Other assets			1,000,000				11,000,000					1,000,000	11,000,000
Total assets			98,000,000				443,000,000					98,000,000	443,000,000
Assets held as collateral			43,000,000				320,000,000					43,000,000	320,000,000
LIABILITIES
Accounts payable and accrued expenses			6,000,000				11,000,000					6,000,000	11,000,000
Mortgage warehouse and advance facilities			40,000,000				300,000,000					40,000,000	300,000,000
Other liabilities			5,000,000				5,000,000					5,000,000	5,000,000
Total liabilities			51,000,000				316,000,000					51,000,000	316,000,000
Company Involvement with Variable Interest Entity
Net loss												47,000,000	16,000,000	28,000,000
PHH Corporation investment			32,000,000				57,000,000					32,000,000	57,000,000
Intercompany receivable			6,000,000				13,000,000					$ 6,000,000	13,000,000
Variable Interest Entities
Ownership percentage												50.10%
Ownership percentage by Realogy												49.90%
Originated residential mortgage loans												$ 5,400,000,000	7,100,000,000	7,900,000,000
Residential mortgage loans brokered or sold												1,700,000,000	2,000,000,000	2,700,000,000
Outstanding commitments related to residential mortgage loans			39,000,000									39,000,000
Distributions received												60,000,000	8,000,000	10,000,000
PHH Home Loans | Variable Interest Entity | Unsecured subordinated Intercompany Line of Credit
Variable Interest Entities
Intercompany line of credit			0				0					0	0
Servicing Advance Receivables Trust | Variable Interest Entity
ASSETS
Cash			0				0					0	0
Restricted cash			10,000,000				19,000,000					10,000,000	19,000,000
Mortgage loans held for sale			0				0					0	0
Accounts receivable, net			0				0					0	0
Servicing advances, net			56,000,000				150,000,000					56,000,000	150,000,000
Property and equipment, net			0				0					0	0
Other assets			0				1,000,000					0	1,000,000
Total assets			66,000,000				170,000,000					66,000,000	170,000,000
Assets held as collateral			66,000,000				169,000,000					66,000,000	169,000,000
LIABILITIES
Accounts payable and accrued expenses			0				0					0	0
Mortgage warehouse and advance facilities			32,000,000				99,000,000					32,000,000	99,000,000
Other liabilities			0				0					0	0
Total liabilities			32,000,000				99,000,000					32,000,000	99,000,000
Company Involvement with Variable Interest Entity
Net loss												(3,000,000)	(4,000,000)	$ (5,000,000)
PHH Corporation investment			51,000,000				83,000,000					51,000,000	83,000,000
Intercompany receivable			$ 0				$ 0					0	$ 0
Variable Interest Entities
Distributions received												401,000,000
Contributed accounts receivable												$ 367,000,000
Realogy and its affiliates | Mortgage loan originations | Credit concentration
Variable Interest Entities
Concentration risk, percentage												28.00%
Reorganization
Variable Interest Entities
Exit and disposal costs												$ 35,000,000
PHH Home Loans Joint Venture | Reorganization
Variable Interest Entities
Exit and disposal costs												$ 13,000,000

[1] The Consolidated Balance Sheets include assets of variable interest entities which can be used only to settle the obligations and liabilities of variable interest entities which creditors or beneficial interest holders do not have recourse to PHH Corporation and subsidiaries as follows: December 31, 2017 2016ASSETS Cash and cash equivalents$33 $67Restricted cash13 24Mortgage loans held for sale60 350Accounts receivable, net1 9Servicing advances, net56 150Property and equipment, net— 1Other assets1 12Total assets$164 $613 LIABILITIES Accounts payable and accrued expenses$6 $11Mortgage warehouse and advance facilities72 399Other liabilities5 5Total liabilities$83 $415