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Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

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Stockholders' Equity - Dividends (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended								12 Months Ended			0 Months Ended
	Dec. 22, 2014	Nov. 06, 2014	Sep. 15, 2014	Aug. 05, 2014	Jun. 16, 2014	May 02, 2014	Mar. 24, 2014	Feb. 07, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 27, 2015
Class of Stock [Line Items]
Dividends declared (in dollars per share)		$ 0.13		$ 0.11		$ 0.11		$ 0.11	$ 0.46	$ 0.3	$ 0.45
Dividends paid (in dollars per share)									$ 0.46	$ 0.30	$ 0.45
Cash payment amount	$ 3.0us-gaap_PaymentsOfDividendsCommonStock		$ 2.6us-gaap_PaymentsOfDividendsCommonStock		$ 2.5us-gaap_PaymentsOfDividendsCommonStock		$ 2.6us-gaap_PaymentsOfDividendsCommonStock		$ 10.7us-gaap_PaymentsOfDividendsCommonStock	$ 7.1us-gaap_PaymentsOfDividendsCommonStock	$ 10.3us-gaap_PaymentsOfDividendsCommonStock
Subsequent Event [Member]
Class of Stock [Line Items]
Dividends declared (in dollars per share)												$ 0.13