Fair Value of Financial Instruments, Derivative Contracts (Details) - Sep. 30, 2015 - Foreign Exchange Forward Contracts € in Millions, £ in Millions, NOK in Millions, MYR in Millions, $ in Millions	USD ($)	MYR	NOK	EUR (€)	GBP (£)
Buy
Derivative [Line Items]
Notional Amount	$ 64	MYR 219	NOK 817	€ 171	£ 118
Buy | 2015
Derivative [Line Items]
Notional Amount	16	143	187	65	94
Buy | 2016
Derivative [Line Items]
Notional Amount	44	76	598	69	22
Buy | 2017
Derivative [Line Items]
Notional Amount	4	0	32	37	2
Sell
Derivative [Line Items]
Notional Amount	711	16	129	33	6
Sell | 2015
Derivative [Line Items]
Notional Amount	282	16	51	23	5
Sell | 2016
Derivative [Line Items]
Notional Amount	327	0	74	10	1
Sell | 2017
Derivative [Line Items]
Notional Amount	101	0	4	0	0
Sell | 2018
Derivative [Line Items]
Notional Amount	$ 1	MYR 0	NOK 0	€ 0	£ 0