Maximum value of stock that may be offered and sold under the demand offering sales agreement.

No definition available.

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- Definition

Represents the number of vesting requirements for awards under an equity-based compensation plan.

+ References

No definition available.

+ Details

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- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ 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

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

+ Details

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- Definition

The cash inflow from the additional capital contribution to the 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 14

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

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Balance Type:	debit
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- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Details

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

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

+ Details

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ 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

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of new stock issued during the period.

+ 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 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

Reference 4: 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

- Details

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Balance Type:	na
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- Details

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- Details

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Namespace Prefix:
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Period Type:

- Details

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- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_IPOMember
Namespace Prefix:
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- Details

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Namespace Prefix:
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Stockholders' Equity (Details) (USD $)	12 Months Ended		0 Months Ended
Stockholders' Equity (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2014 item	May 15, 2013	May 06, 2010
Equity offerings
Proceeds from the issuance of common stock, net	$ 241,500,000
Offering related expenses incurred	10,818,000us-gaap_PaymentsOfStockIssuanceCosts
2002 Stock Incentive Plan
Equity-Based Compensation
Maximum number of shares provided for grant under equity-based incentive compensation plan		2,000,000
Number of vesting requirements		0
Number of shares available for grant under the plan		1,944,428
May 2013 Public Offering and Underwriter Overallotment Option
Equity offerings
Shares of common stock sold			17,250,000
Price per share of common stock sold (in dollars per share)			$ 14.00
May 2013 Public Offering Underwriter Overallotment Option
Equity offerings
Shares of common stock sold			2,250,000
May 2013 Public Offering
Equity offerings
Proceeds from the issuance of common stock, net			230,700,000
Offering related expenses incurred			10,800,000
ATM Sales Program
Equity offerings
Maximum aggregate gross sales price of common stock		34,300,000		$ 75,000,000