Commitments and Contingencies - Additional Information (Detail)	0 Months Ended			12 Months Ended					0 Months Ended
	Dec. 31, 2014 USD ($)	Sep. 28, 2012 Plaintiff	Apr. 23, 2007	Dec. 31, 2014 USD ($) Agreement	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	May 31, 2012 USD ($)	Mar. 09, 2010 USD ($)	Feb. 10, 2015 Subsequent Event [Member] USD ($) Plaintiff	Jul. 23, 2014 Property Damages [Member] EUR (€)	Jul. 23, 2014 Business Interruption [Member] EUR (€)
Contingencies And Commitments [Line Items]
Rent expense, net of sublease income				$ 140,000,000	$ 141,000,000	$ 145,000,000
Sublease rental income				4,000,000	6,000,000	5,000,000
Total outstanding letters of credit				615,000,000	634,000,000
Available borrowings under Credit Facility				1,000,000,000	1,000,000,000
Number of existing real estate lease agreements				2
Real estate lease agreements, expiry date				Aug. 31, 2015
Purchase price of property on or before expiration date				28,000,000
Residual guarantee amount				23,000,000
Maximum amount of supplemental rent payment				5,000,000
Aggregate residual guarantee amount				23,000,000
Term for operating lease agreements (in years)				15 years
Fair market value of simulator systems, Minimum				7,000,000
Fair market value of simulator systems, Maximum				21,000,000
Additional rent to be paid for simulator systems after expiration date				7,000,000
Charges in connection with anticipated settlement				18,000,000
Receivables for recoveries from insurance contracts	11,000,000
Number of plaintiffs re-filed their complaint against ACSS			30
Compensatory damages							48,000,000	6,700,000
Number of plaintiffs released their claims against ACSS		18
Number of plaintiffs settled their claims against ACSS									12
Aggregate expenses incurred by plaintiff									11,000,000
Claims for estimated damages										€ 11,000,000	€ 35,000,000