Financial Instruments - Carrying Amount and Estimated Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, at fair value	$ 326,853	[1]	$ 405,505	[1]
Credit facilities and bank overdrafts	4,747	[2]	984	[2]
Senior Notes, Noncurrent			299,736	[3]
Reported Value Measurement [Member] | Senior Notes In Two Thousand Seven [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	500,000	[3]	500,000	[3]
Reported Value Measurement [Member] | Senior Notes In Two Thousand Six [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	125,000	[3]	125,000	[3]
Reported Value Measurement [Member] | Senior Notes In Two Thousand Thirteen [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	299,767	[3]
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, at fair value	326,853	[1]	405,505	[1]
Credit facilities and bank overdrafts	4,747	[2]	984	[2]
Estimate of Fair Value Measurement [Member] | Senior Notes In Two Thousand Seven [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	596,115	[3]	590,024	[3]
Estimate of Fair Value Measurement [Member] | Senior Notes In Two Thousand Six [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	136,148	[3]	139,146	[3]
Estimate of Fair Value Measurement [Member] | Senior Notes In Two Thousand Thirteen [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Noncurrent	$ 292,620	[3]	$ 278,770	[3]

[1] The carrying amount of cash and cash equivalents approximates fair value due to the short maturity of those instruments.

[2] The carrying amount of our credit facilities and bank overdrafts approximates fair value as the interest rate is reset frequently based on current market rates as well as the short maturity of those instruments.

[3] The fair value of our long-term debt was calculated using discounted cash flows applying current interest rates and current credit spreads based on our own credit risk.