Acquisition of Crexus - Narrative (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2013	Dec. 31, 2013
Business Acquisition [Line Items]
Business acquisition agreement date		Jan. 30, 2013
Goodwill	$ 71.4
Goodwill adjustment		0.4
Business combination loss recognized	18.9
Business acquisition transaction cost		$ 7.3

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Goodwill

No definition available.

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Period Type:	instant

- Definition

Goodwill Adjustment Related To Business Acquisition

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionDateOfAcquisitionAgreement1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=21917927&loc=d3e1043-128460

+ Details

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Period Type:	duration

- Definition

In a business combination achieved in stages, this element represents the amount of loss recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementLoss
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Data Type:	xbrli:monetaryItemType
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