v3.19.1

Debt (Debt Textuals) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Mar. 31, 2018	Apr. 05, 2019
Line of Credit Facility [Line Items]
Gain (Loss) on Extinguishment of Debt		$ 4	$ 0
Debt Instruments [Abstract]
Debt Instrument, Interest Rate, Effective Percentage		5.90%	5.60%
CDHI [Member]
Line of Credit Facility [Line Items]
Future Line of Credit Facility Maximum Borrowing Capacity		$ 125
Other Corporate Facilities [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		200
2026 First Lien Term Loan [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount				$ 950
Percentage of principal amount of Term Loan to be paid quarterly	0.25%
Debt Instrument Unamortized Discount Percent				1.00%
Debt Issuance Costs, Net				$ 7
Gain (Loss) on Extinguishment of Debt	$ (3)
Amendment No. 6 [Member] | Subsequent Event [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Increase (Decrease), Net	330
Line of Credit Facility, Maximum Borrowing Capacity				$ 2,020
Amendment No. 8 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,690
Goldman Sachs - Amendment No 3 [Member] | Subsequent Event [Member] | Other Corporate Facilities [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Increase (Decrease), Net	$ 100
Federal Funds Effective Rate [Member] | 2026 First Lien Notes [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Eurodollar Rate For A One-Month Interest Period [Member] | 2026 First Lien Term Loan [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Prime Rate or The Eurodollar Rate For A One-Month Interest Period [Member] | 2026 First Lien Term Loan [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
London Interbank Offered Rate (LIBOR) [Member] | 2026 First Lien Term Loan [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.75%
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | 2026 First Lien Term Loan [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				0.00%

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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