Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3-4)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph a(1)

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

Name:	us-gaap_AccountsReceivableNetCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Trade and Finance Receivables - Trade Receivables (Details) (USD $)							3 Months Ended	6 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2013 Iranian customers	Dec. 31, 2012 Iranian customers	Sep. 30, 2012 Iranian customers	Sep. 30, 2012 Iranian customers Customer not able to find acceptable methods of payment	Dec. 31, 2012 Iranian customers Customer not able to find acceptable methods of payment customer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade receivables, less allowances with Iranian customers	$ 269,892,000	$ 285,151,000	$ 305,036,000	$ 17,000,000	$ 20,000,000	$ 18,000,000
Number of customers not able to find acceptable methods of payment								1
Trade receivables reserved amounts related to one customer							$ 7,000,000	$ 9,000,000