Name:	evk_StockholdersEquityDetailsLineItems
Namespace Prefix:	evk_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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

No definition available.

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

No definition available.

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

Number of shares of stock issued during the period as part of a transaction to acquire assets that do not qualify as a business combination.

No definition available.

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

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Cost basis for treasury stock acquired for purposes other than retirement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655