Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Fair value of assets measured on recurring basis

Our financial instruments measured at fair value on a recurring basis at June 30, 2019, were as follows:

	Total		Observable Inputs (Level 1)		Directly or Indirectly Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	(In millions)
Corporate debt securities	$	1,297	$	—	$	1,297	$	—
Mortgage-backed securities	249		—		249		—
Asset-backed securities	161		—		161		—
Government-sponsored enterprise securities (“GSEs”)	159		—		159		—
Municipal securities	109		—		109		—
U.S. Treasury notes	87		—		87		—
Certificate of deposit	6		—		6		—
Other	2		—		2		—
Subtotal - current investments	2,070		—		2,070		—
1.125% Call Option derivative asset	169		—		—		169
Total assets	$	2,239	$	—	$	2,070	$	169
1.125% Conversion Option derivative liability	$	169	$	—	$	—	$	169
Total liabilities	$	169	$	—	$	—	$	169

Our financial instruments measured at fair value on a recurring basis at December 31, 2018, were as follows:

	Total		Observable Inputs (Level 1)		Directly or Indirectly Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	(In millions)
Corporate debt securities	$	1,123	$	—	$	1,123	$	—
Asset-backed securities	82		—		82		—
GSEs	163		—		163		—
Municipal securities	114		—		114		—
U.S. Treasury notes	181		—		181		—
Certificates of deposit	14		—		14		—
Other	4		—		4		—
Subtotal - current investments	1,681		—		1,681		—
1.125% Call Option derivative asset	476		—		—		476
Total assets	$	2,157	$	—	$	1,681	$	476
1.125% Conversion Option derivative liability	$	476	$	—	$	—	$	476
Total liabilities	$	476	$	—	$	—	$	476

Schedule of fair value, asset and liabilities measured on recurring basis - disclosure only

The carrying amounts and estimated fair values of our notes payable are classified as Level 2 financial instruments. Fair value for these securities is determined using a market approach based on quoted market prices for similar securities in active markets or quoted prices for identical securities in inactive markets. The carrying amount and estimated fair value of the Term Loan Facility is classified as a Level 3 financial instrument, because certain inputs used to determine its fair value are not observable. As of June 30, 2019, the carrying amount of the Term Loan Facility approximates fair value because its interest rate is a variable rate that approximates rates currently available to us.

	June 30, 2019				December 31, 2018
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(In millions)
5.375% Notes	$	695	$	732	$	694	$	674
4.875% Notes	326		335		326		301
Term Loan Facility	220		220		—		—
1.125% Convertible Notes (1),(2)	65		231		240		732
Totals	$	1,306	$	1,518	$	1,260	$	1,707

______________________

(1) The fair value of the 1.125% Conversion Option (the embedded cash conversion option), which is reflected in the fair value amounts presented above, amounted to $169 million and $476 million as of June 30, 2019, and December 31, 2018, respectively. See further discussion at Note 7, “Debt,” and Note 8, “Derivatives.”

(2)

For more information on debt repayments in 2019, refer to Note 7, “Debt.”