Amount of additional stock repurchase plan authorization.

No definition available.

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

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)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

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- Definition

The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

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-Section 50

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-Topic 230

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- Definition

Number of share instruments newly issued under a share-based compensation plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of shares issued which are neither cancelled nor held in the treasury.

+ References

No definition available.

+ Details

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- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

+ Details

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ 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

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-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

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-Topic 505

-SubTopic 30

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Shareholders’ equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	44 Months Ended	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015	Mar. 26, 2015	Dec. 31, 2014	Aug. 01, 2011
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	195,000,000us-gaap_CommonStockSharesAuthorized	195,000,000us-gaap_CommonStockSharesAuthorized				195,000,000us-gaap_CommonStockSharesAuthorized
Stock repurchase program, authorized amount	$ 130,000	$ 130,000					$ 60,000
Stock Repurchase Program, Additional Authorized Amount					70,000
Repurchase of common stock (in shares)	1,200,000us-gaap_TreasuryStockSharesAcquired	5,986,521us-gaap_TreasuryStockSharesAcquired
Repurchase of common stock, aggregate purchase price	19,439	69,363
Stock repurchase program, remaining authorized repurchase amount	60,637	60,637
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	1,200,000us-gaap_TreasuryStockSharesAcquired	5,986,521us-gaap_TreasuryStockSharesAcquired
Series A Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)	78,141		79,620
Repurchase of common stock (in shares)	0
Conversion of convertible preferred stock (in shares)	(80)		(255)
Issuance for stock compensation plans (in shares)	0		0
Shares, Ending balance (in shares)	78,061	78,061	79,365
Treasury Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)	1,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)	4,786,521		4,786,521
Repurchase of common stock (in shares)	1,200,000
Conversion of convertible preferred stock (in shares)	0		0
Issuance for stock compensation plans (in shares)	0		0
Shares, Ending balance (in shares)	5,986,521	5,986,521	4,786,521
Common Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)	(1,200,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)	89,064,582		88,710,277
Repurchase of common stock (in shares)	(1,200,000)
Conversion of convertible preferred stock (in shares)	7,947		25,542
Issuance for stock compensation plans (in shares)	10,828		35,624
Shares, Ending balance (in shares)	87,883,357	87,883,357	88,771,443
Subsequent Event [Member]
Class of Stock [Line Items]
Repurchase of common stock, aggregate purchase price				$ 7,022