jpa/subsystem/src/main/java/org/jboss/as/jpa/config/Configuration.java
public static boolean deferEntityDetachUntilClose(final Map<String, Object> properties) {
        boolean result = false;
        if ( properties.containsKey(JPA_DEFER_DETACH))
            result = Boolean.parseBoolean((String)properties.get(JPA_DEFER_DETACH));
        return result;
    }
public static boolean deferEntityDetachUntilClose(final Map<String, Object> properties) {
        boolean result = false;
        if ( properties.containsKey(JPA_DEFER_DETACH))
            result = Boolean.parseBoolean((String)properties.get(JPA_DEFER_DETACH));
        return result;
    }
Return true if detaching of managed entities should be deferred until the entity manager is closed.
Note:  only applies to transaction scoped entity managers used without an active JTA transaction.

@param properties
@return