Restatement - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable	$ 671	$ 671
Inventories, net	397	394
Prepaid expenses and other current assets	70	53
Total Current assets	1,334	1,672
Goodwill	2,490	2,490	$ 156
Other long-term assets	91
Total Assets	5,040	5,539
Long-term deferred income taxes	70	0
Accrued liabilities	367	421
Deferred revenue	197	196
Income taxes payable	42	5
Total Current liabilities	895	953
Other long-term liabilities	115	74
Total liabilities	4,147	4,499
Retained earnings	1,377	1,535
Accumulated other comprehensive loss	(48)	(9)	(9)	$ (10)
Total Stockholders' Equity	893	1,040	$ 959	$ 857
Total Liabilities and Stockholders' Equity	5,040	$ 5,539
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable	674
Inventories, net	394
Prepaid expenses and other current assets	68
Total Current assets	1,332
Goodwill	2,493
Other long-term assets	92
Total Assets	5,024
Long-term deferred income taxes	52
Accrued liabilities	358
Deferred revenue	198
Income taxes payable	31
Total Current liabilities	876
Other long-term liabilities	98
Total liabilities	4,111
Retained earnings	1,398
Accumulated other comprehensive loss	(49)
Total Stockholders' Equity	913
Total Liabilities and Stockholders' Equity	5,024
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable	(3)
Inventories, net	3
Prepaid expenses and other current assets	2
Total Current assets	2
Goodwill	(3)
Other long-term assets	(1)
Total Assets	16
Long-term deferred income taxes	18
Accrued liabilities	9
Deferred revenue	(1)
Income taxes payable	11
Total Current liabilities	19
Other long-term liabilities	17
Total liabilities	36
Retained earnings	(21)
Accumulated other comprehensive loss	1
Total Stockholders' Equity	(20)
Total Liabilities and Stockholders' Equity	$ 16