XML 34 R75.htm IDEA: XBRL DOCUMENT v3.2.0.727

Stock-Based Compensation (Details 4) - Jun. 30, 2015 - Employee Stock Purchase Plan - USD ($)	Total
Employee Stock Purchase Plan
Maximum employee salary to purchase shares (in dollars)	$ 25,000
Maximum percentage of employee eligible pay to purchase shares	10.00%
Minimum
Employee Stock Purchase Plan
Purchase price as a percent of the fair market value	85.00%
Maximum
Employee Stock Purchase Plan
Purchase price as a percent of the fair market value	100.00%

X

- Definition

The highest amount of annual salary that an employee is permitted to utilize with respect to the plan.

+ References

No definition available.

+ Details

Name:	exh_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionAmount
Namespace Prefix:	exh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the 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

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_PlanNameAxis=us-gaap_EmployeeStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: