(6) Net Investment in Sales-Type and Direct Finance Leases

The following table represents the components of the Company’s net investment in sales-type and direct finance leases (in thousands):



	September 30,		December 31,
	2019		2018
Gross sales-type and finance lease receivables (1)	$	781,624	$	804,511
Unearned income (2)		(241,857)		(254,744)
Net investment in sales-type and direct finance leases	$	539,767	$	549,767

(1)At the inception of the lease, the Company records the total minimum lease payments, executory costs, if any, and unguaranteed residual value as gross sales-type and finance lease receivables. The gross sales-type and finance lease receivables are reduced as customer payments are received. There was $74.3 million and $74.4 million of unguaranteed residual value at September 30, 2019 and December 31, 2018, respectively, included in gross sales-type and finance lease receivables. There were no executory costs included in gross sales-type and finance lease receivables as of September 30, 2019 and December 31, 2018.

(2)The difference between the gross sales-type and finance lease receivables and the cost of the equipment or carrying amount at the lease inception is recorded as unearned income. Unearned income, together with initial direct costs, are amortized to income over the lease term so as to produce a constant periodic rate of return. There were no unamortized initial direct costs as of September 30, 2019 and December 31, 2018.

In order to estimate the allowance for losses contained in gross sales-type and finance lease receivables, the Company reviews the credit worthiness of its customers on an ongoing basis. The review includes monitoring credit quality indicators, the aging of customer receivables and general economic conditions.

The categories of gross finance lease receivables based on the Company's internal customer credit ratings can be described as follows:

Tier 1— These customers are typically large international shipping lines that have been in business for many years and have world-class operating capabilities and significant financial resources. In most cases, the Company has had a long commercial relationship with these customers and currently maintains regular communication with them at several levels of management, which provides the Company with insight into the customer's current operating and financial performance. In the Company's view, these customers have the greatest ability to withstand cyclical down turns and would likely have greater access to needed capital than lower-rated customers. The Company views the risk of default for Tier 1 customers to range from minimal to moderate.

Tier 2— These customers are typically either smaller shipping lines or freight forwarders with less operating scale or with a high degree of financial leverage, and accordingly the Company views these customers as subject to higher volatility in financial performance over the business cycle. The Company generally expects these customers to have less access to capital markets or other sources of financing during cyclical down turns. The Company views the risk of default for Tier 2 customers as moderate.

Tier 3— Customers in this category exhibit volatility in payments on a regular basis.

Based on the above categories, the Company's gross sales-type and finance lease receivables were as follows (in thousands):



	September 30,		December 31,
	2019		2018
Tier 1	$	714,921	$	698,014
Tier 2		66,703		106,497
Tier 3		-		-
	$	781,624	$	804,511

Contractual maturities of the Company's gross sales-type and finance lease receivables subsequent to September 30, 2019 for the years ending September 30 are as follows (in thousands):


2020	$	109,400
2021		98,955
2022		91,883
2023		91,211
2024		61,405
2025 and thereafter		328,770
	$	781,624