Restructuring-Related Liabilities: (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Current Liability
Restructuring Reserve
Liability at the beginning of the period	$ 30
Payments	(23)
Other Adjustments	24
Liability at the end of the period	31
Noncurrent Liability
Restructuring Reserve
Liability at the beginning of the period	430
Other Adjustments	1
Liability at the end of the period	430
Workforce | Current Liability
Restructuring Reserve
Liability at the beginning of the period	28
Payments	(22)
Other Adjustments	25
Liability at the end of the period	31
Workforce | Noncurrent Liability
Restructuring Reserve
Liability at the beginning of the period	430
Other Adjustments	1
Liability at the end of the period	430
Space | Current Liability
Restructuring Reserve
Liability at the beginning of the period	2
Payments	(1)
Other Adjustments	(1)
Liability at the end of the period	0
Space | Noncurrent Liability
Restructuring Reserve
Liability at the beginning of the period	0
Other Adjustments	0
Liability at the end of the period	$ 0