Other Comprehensive Income (Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive (Loss) Income, Beginning Balance	$ (53)	$ (90)	$ (62)	$ (73)
Other comprehensive income (loss) before reclassifications	3	(7)		(48)
Amounts reclassified from accumulated other comprehensive income	5	10	17	32
Other comprehensive income (loss)	8	3	17	(16)
AOCI distributed to QHC in spin-off				2
Accumulated Other Comprehensive (Loss) Income, Ending Balance	(45)	(87)	(45)	(87)
Change in Fair Value of Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive (Loss) Income, Beginning Balance	(28)	(69)	(31)	(48)
Other comprehensive income (loss) before reclassifications	1		(7)	(40)
Amounts reclassified from accumulated other comprehensive income	4	10	15	29
Other comprehensive income (loss)	5	10	8	(11)
Accumulated Other Comprehensive (Loss) Income, Ending Balance	(23)	(59)	(23)	(59)
Change in Fair Value of Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive (Loss) Income, Beginning Balance	(5)		(10)	1
Other comprehensive income (loss) before reclassifications	2	(7)	7	(8)
Amounts reclassified from accumulated other comprehensive income
Other comprehensive income (loss)	2	(7)	7	(8)
AOCI distributed to QHC in spin-off
Accumulated Other Comprehensive (Loss) Income, Ending Balance	(3)	(7)	(3)	(7)
Change in Unrecognized Pension Cost Components [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive (Loss) Income, Beginning Balance	(20)	(21)	(21)	(26)
Amounts reclassified from accumulated other comprehensive income	1		2	3
Other comprehensive income (loss)	1		2	3
AOCI distributed to QHC in spin-off				2
Accumulated Other Comprehensive (Loss) Income, Ending Balance	$ (19)	$ (21)	$ (19)	$ (21)