Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References+ Details

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

+ References+ Details

- Definition

Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time. Because of their short-term, time deposits are considered highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References+ Details

Fair Value of Financial Instruments - Cash and Cash Equivalents (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	$ 1,247,652	$ 1,260,842	$ 1,294,356	$ 1,084,465
Total short-term investments	26,337	139
Cost
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	1,247,652	1,260,842
Total short-term investments	26,337	139
Total	1,273,989	1,260,981
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	1,247,719	1,260,844
Total short-term investments	26,362	139
Total	1,274,081	1,260,983
Cash and Cash Equivalents \| Cost
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and overnight deposits	590,317	458,169
Corporate commercial paper	629,923	642,884
Time deposits	27,412	159,789
Cash and Cash Equivalents \| Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and overnight deposits	590,317	458,169
Corporate commercial paper	629,990	642,886
Time deposits	27,412	159,789
Short-term Investments \| Cost
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Corporate commercial paper	26,296	0
Time deposits	41	139
Short-term Investments \| Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Corporate commercial paper	26,321	0
Time deposits	$ 41	$ 139