Maintenance Reserves and Accrued Maintenance Costs	12 Months Ended
Dec. 31, 2014
Maintenance Reserves and Accrued Maintenance Costs [Abstract]
Maintenance Reserves and Accrued Maintenance Costs	4.Maintenance Reserves and Accrued Maintenance Costs Maintenance costs under the Company’s triple net leases are generally the responsibility of the lessees. Most of the Company’s leases require payment of maintenance reserves, which are based upon lessee-reported usage and billed monthly, and are intended to accumulate and be applied by the Company toward reimbursement of most or all of the cost of the lessees’ performance of certain maintenance obligations under the leases. Maintenance reserves are characterized as either refundable or non-refundable depending on their disposition at lease-end. The Company retains non-refundable maintenance reserves at lease-end, even if the lessee has met all of its obligations under the lease, including any return conditions applicable to the leased asset, while refundable reserves are returned to the lessee under such circumstances. The liabilities for maintenance reserves in the accompanying balance sheets include both refundable and non-refundable maintenance reserves payments billed to and received from lessees. These amounts are paid out as related maintenance is performed and, in the case of refundable reserves, at the end of the lease. Such payments reduce the associated maintenance reserve liability. Any reserves retained by the Company at lease end are recorded as revenue at that time. Accrued maintenance costs include (i) maintenance for work performed for off-lease aircraft, which is not related to the release of reserves received from lessees and (ii) lessor maintenance obligations assumed upon acquisition of aircraft subject to a lease with such provisions. Maintenance costs are expensed as incurred.

4.Maintenance Reserves and Accrued Maintenance Costs

Maintenance costs under the Company’s triple net leases are generally the responsibility of the lessees. Most of the Company’s leases require payment of maintenance reserves, which are based upon lessee-reported usage and billed monthly, and are intended to accumulate and be applied by the Company toward reimbursement of most or all of the cost of the lessees’ performance of certain maintenance obligations under the leases. Maintenance reserves are characterized as either refundable or non-refundable depending on their disposition at lease-end. The Company retains non-refundable maintenance reserves at lease-end, even if the lessee has met all of its obligations under the lease, including any return conditions applicable to the leased asset, while refundable reserves are returned to the lessee under such circumstances.

The liabilities for maintenance reserves in the accompanying balance sheets include both refundable and non-refundable maintenance reserves payments billed to and received from lessees. These amounts are paid out as related maintenance is performed and, in the case of refundable reserves, at the end of the lease. Such payments reduce the associated maintenance reserve liability. Any reserves retained by the Company at lease end are recorded as revenue at that time.

Accrued maintenance costs include (i) maintenance for work performed for off-lease aircraft, which is not related to the release of reserves received from lessees and (ii) lessor maintenance obligations assumed upon acquisition of aircraft subject to a lease with such provisions. Maintenance costs are expensed as incurred.