Allowance for Credit Losses of Financing Receivables and its Recorded Investment (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Allowance for credit losses:
Ending balance
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment
Ending balance: loans acquired with deteriorated credit quality
Financing receivables:
Ending balance	167	256
Ending balance: individually evaluated for impairment	167	256
Ending balance: collectively evaluated for impairment
Ending balance: loans acquired with deteriorated credit quality
Finance leases
Allowance for credit losses:
Ending balance
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment
Ending balance: loans acquired with deteriorated credit quality
Financing receivables:
Ending balance	167	256
Ending balance: individually evaluated for impairment	167	256
Ending balance: collectively evaluated for impairment
Ending balance: loans acquired with deteriorated credit quality