Accounts Payable and Accrued Expenses - Components of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accounts payable	$ 392,646	$ 533,900
Payroll and benefits, including incentive compensation	138,805	67,480
Health insurance, workers’ compensation and other insurance costs	62,277	52,851
Current derivative liability	10,023	4,392
Customer rebates	49,053	47,658
Other accrued liabilities	89,184	68,619
Total	$ 741,988	$ 774,900