Face amount per share of no-par value common stock.

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 210.5-02.29)

-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 30

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ 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 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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SUBSEQUENT EVENT (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Apr. 01, 2015
Subsequent events
Common stock, par value (in dollars per share)	$ 0us-gaap_CommonStockNoParValue		$ 0us-gaap_CommonStockNoParValue
Number of shares repurchased	473,829	3,405,888
Common Stock
Subsequent events
Number of shares repurchased			857,554
Value of shares repurchased			$ 16.5
Subsequent Event \| Common Stock
Subsequent events
Remaining amount available for repurchase	29.2
Subsequent Event \| Common Stock \| Underwriting Agreement
Subsequent events
Common stock, par value (in dollars per share)				$ 0
Common stock, sale price (in dollars per share)				$ 23.01
Value of shares repurchased				175.0
Subsequent Event \| Common Stock \| Underwriting Agreement \| Carlyle
Subsequent events
Number of shares repurchased				3,802,694
Subsequent Event \| Common Stock \| Underwriting Agreement \| Anchorage
Subsequent events
Number of shares repurchased				3,802,694
Subsequent Event \| Common Stock \| Underwriting Agreement \| Carlyle And Anchorage
Subsequent events
Common stock, sale price (in dollars per share)				$ 23.01
Number of shares repurchased				7,605,388
Subsequent Event \| Common Stock \| Underwriting Agreement \| Citigroup Global Markets
Subsequent events
Common stock, sale price (in dollars per share)				$ 23.01
Number of shares repurchased				3,259,452
Value of shares repurchased				$ 75.0