XML 34 R54.htm IDEA: XBRL DOCUMENT v2.4.1.9
Related Party Transactions - Summary of Deposits and Withdrawals Made by Related Parties (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Deposits and Withdrawals $120000 or More    
Related Party Transaction [Line Items]    
Deposits $ 300,000ck0001409970_RelatedPartyDeposits
/ us-gaap_RelatedPartyTransactionAxis
= ck0001409970_DepositsAndWithdrawals120000OrMoreMember		 $ 200,000ck0001409970_RelatedPartyDeposits
/ us-gaap_RelatedPartyTransactionAxis
= ck0001409970_DepositsAndWithdrawals120000OrMoreMember
Withdrawals 300,000ck0001409970_RelatedPartyWithdrawals
/ us-gaap_RelatedPartyTransactionAxis
= ck0001409970_DepositsAndWithdrawals120000OrMoreMember		  
Minimum    
Related Party Transaction [Line Items]    
Related party transaction threshold $ 120,000ck0001409970_RelatedPartyTransactionThreshold
/ us-gaap_RangeAxis
= us-gaap_MinimumMember