Sales of Accounts Receivable and Receivable Discount Program - Additional Information (Detail) (Trade Accounts Receivable [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of accounts receivable	$ 25,485	$ 3,139
Selling, general and administrative expenses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Pre-tax losses on accounts receivable	$ 22	$ 8