Debt (Tables)

9 Months Ended

Sep. 30, 2016

Debt Disclosure [Abstract]

Schedule of maturities of long-term debt

As of September 30, 2016, contractual maturities of debt for the years ending December 31 are as follows:

	Total		2016		2017		2018		2019		2020		Thereafter
	(In millions)
5.375% Notes	$	700	$	—	$	—	$	—	$	—	$	—	$	700
1.125% Convertible Notes	550		—		—		—		—		550		—
1.625% Convertible Notes (1)	302		—		—		—		—		—		302
	$	1,552	$	—	$	—	$	—	$	—	$	550	$	1,002

(1) The 1.625% Notes have a contractual maturity date in 2044; however, on contractually specified dates beginning in 2018, holders of the 1.625% Notes may require us to repurchase some or all of the 1.625% Notes, or we may redeem any or all of the 1.625% Notes.

Long term debt

Substantially all of our debt is held at the parent, which is reported in the Other segment. The principal amounts, unamortized discount (net of premium related to the 1.625% Notes), unamortized issuance costs, and net carrying amounts of debt were as follows:

	Principal Balance		Unamortized Discount		Unamortized Issuance Costs		Net Carrying Amount
	(In millions)
September 30, 2016:
5.375% Notes	$	700	$	—	$	10	$	690
1.125% Convertible Notes	550		78		6		466
1.625% Convertible Notes	302		18		3		281
	$	1,552	$	96	$	19	$	1,437
December 31, 2015:
5.375% Notes	$	700	$	—	$	11	$	689
1.125% Convertible Notes	550		95		7		448
1.625% Convertible Notes	302		25		4		273
Other	1		—		—		1
	$	1,553	$	120	$	22	$	1,411

Debt instruments interest cost recognized

Interest cost recognized relating to our convertible senior notes for the periods presented was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
	(In millions)
Contractual interest coupon rate	$	2	$	3	$	8	$	9
Amortization of the discount	7		7		22		21
	$	9	$	10	$	30	$	30