Derivatives - Additional Information (Detail) (USD $)											12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Interest Rate Swaps [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2012 Interest Rate Swaps [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Foreign Exchange Swaps [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2012 Foreign Exchange Swaps [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Equity Options [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2012 Equity Options [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 4.50% Convertible Notes [Member]	Dec. 31, 2012 4.50% Convertible Notes [Member]	Jul. 29, 2011 4.50% Convertible Notes [Member]	Dec. 31, 2013 Capped Call [Member]	Dec. 31, 2013 Capped Call [Member] 4.50% Convertible Notes [Member]	Dec. 31, 2013 Embedded Conversion Feature [Member] 4.50% Convertible Notes [Member]
Option Indexed to Issuer's Equity [Line Items]
Notional amounts of the transactions		$ 87,800,000	$ 361,800,000	$ 197,400,000	$ 233,500,000	$ 59,700,000	$ 0
Replacement cost of contracts in a gain position	1,600,000
Adjustments to paid-in capital												11,400,000	19,000,000
Adjustments to paid in capital, net of tax and issuance costs											9,900,000	9,900,000	16,100,000
Principal amount of debt component								$ 160,000,000	$ 160,000,000	$ 160,000,000
Stated interest rate								4.50%	4.50%	4.50%