Organization and Nature of Business and Summary of Significant Accounting Policies (Subsidiaries) (Details)	Jun. 30, 2014
ICD IV, LLC [Member]
Organization and Nature of Business [Line Items]
Ownership percentage of less than wholly owned consolidated subsidiaries	99.99%

The ownership percentage of less than wholly owned subsidiaries which are included in the consolidated financial statements.

No definition available.

Name:	wtba_ConsolidatedSubsidiariesLessThanWhollyOwnedOwnershipPercentage
Namespace Prefix:	wtba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant