Debt Debt (Schedule of Senior Notes) (Details) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended			1 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended
Sep. 30, 2014 Senior Unsecured Notes Due 2019 [Member]	Mar. 31, 2015 Senior Unsecured Notes Due 2019 [Member]	Mar. 31, 2014 Senior Unsecured Notes Due 2019 [Member]	Dec. 31, 2014 Senior Unsecured Notes Due 2019 [Member]	Sep. 24, 2014 Senior Unsecured Notes Due 2019 [Member] EUR (€)	Nov. 30, 2012 Senior Unsecured Notes Due 2022 [Member] USD ($)	Mar. 31, 2015 Senior Unsecured Notes Due 2022 [Member]	Mar. 31, 2014 Senior Unsecured Notes Due 2022 [Member]	Dec. 31, 2014 Senior Unsecured Notes Due 2022 [Member]	May 31, 2011 Senior Unsecured Notes Due 2021 [Member] USD ($)	Mar. 31, 2015 Senior Unsecured Notes Due 2021 [Member]	Mar. 31, 2014 Senior Unsecured Notes Due 2021 [Member]	Dec. 31, 2014 Senior Unsecured Notes Due 2021 [Member]
Debt Instrument [Line Items]
Senior notes					€ 300	$ 500				$ 400
Interest rate		3.25%		3.25%	3.25%	4.625%	4.625%		4.625%	5.875%	5.875%		5.875%
Date of maturity	Oct. 15, 2019	Oct. 15, 2019	Oct. 15, 2019			Nov. 15, 2022	Nov. 15, 2022	Nov. 15, 2022		Jun. 15, 2021	Jun. 15, 2021	Jun. 15, 2021

Face (par) amount of debt instrument at time of issuance.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

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

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