Subsequent event (Details) - Accounts Receivable [Member] - USD ($) $ in Millions	Nov. 06, 2015	May. 16, 2014
Subsequent Event [Line Items]
Maximum Funding Limit		$ 3,300
Future lease receivables [Member] \| Future lease receivables [Member]
Subsequent Event [Line Items]
Line of credit facility, additional borrowing capacity	$ 700
Maximum Funding Limit	$ 4,000

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration