Employee Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Employee waiting period after hire to participate in the defined contribution plans	90 days
Employee maximum contribution towards defined contribution plans as percentage of annual compensation	25.00%
Employer's match in cash of employee contributions on first specified percentage of eligible compensation	100.00%
First percentage of eligible compensation on which specified percentage of contribution is matched by the employer in cash	3.00%
Employer's match in cash of employee contributions on next specified percentage of eligible compensation	50.00%
Next percentage of eligible compensation on which specified percentage of contribution is matched by the employer in cash	3.00%
Employer maximum match of employee contribution on eligible compensation	4.50%
Operating, selling, general and administrative expenses for our defined contribution plans	$ 63	$ 63	$ 63
Accrued benefit liabilities for defined benefit pension and other post retirement plans	64
Charge to "Operating" expenses for the agreed-upon withdrawal of bargaining units from multi-employer pension plans	4	5	10
Contributions to Multi employer Plan	44	40	39
Multiemployer Health And Welfare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to Multi employer Plan	34	34	36
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded benefit obligation of pension and other post-retirement plans	33
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Combined accumulated benefit obligation of pension plans	121
Plan assets of pension plans	90
Unfunded benefit obligation of pension and other post-retirement plans	$ 31