Note 4.Debt Financing

The Company's debt financing was comprised of the following at June 30, 2018 and December 31, 2017 (dollars in thousands):


	June 30, 2018		December 31, 2017
Unsecured
Senior notes	$	9,268,445	$	8,019,871
Revolving credit facility		956,000		847,000
Convertible senior notes		199,951		199,983
Term financings		183,838		203,704
Total unsecured debt financing		10,608,234		9,270,558
Secured
Term financings		428,951		484,036
Export credit financing		41,593		44,920
Total secured debt financing		470,544		528,956

Total debt financing		11,078,778		9,799,514
Less: Debt discounts and issuance costs		(116,332)		(100,729)
Debt financing, net of discounts and issuance costs	$	10,962,446	$	9,698,785

The Company’s secured obligations as of June 30, 2018 and December 31, 2017 are summarized below (dollars in thousands):


	June 30, 2018		December 31, 2017
Nonrecourse	$	187,616	$	205,906
Recourse		282,928		323,050
Total secured debt financing	$	470,544	$	528,956
Number of aircraft pledged as collateral		21		21
Net book value of aircraft pledged as collateral	$	1,157,994	$	1,184,264

Senior unsecured notes

As of June 30, 2018, the Company had $9.3 billion in senior unsecured notes outstanding. As of December 31, 2017, the Company had $8.0 billion in senior unsecured notes outstanding.

In June 2018, the Company issued $500.0 million in aggregate principal amount of senior unsecured notes due 2023 that bear interest at a rate of 3.875%.

In January 2018, the Company issued (i) $550.0 million in aggregate principal amount of senior unsecured notes due 2021 that bear interest at a rate of 2.50% and (ii) $700.0 million in aggregate principal amount of senior unsecured notes due 2025 that bear interest at a rate of 3.25%.

Unsecured revolving credit facility

In May 2018, the Company amended and extended its unsecured revolving credit facility whereby, among other things, the Company extended the final maturity date from May 5, 2021 to May 5, 2022 and increased the total revolving commitments to approximately $4.5 billion from approximately $4.1 billion with an interest rate of LIBOR plus 1.05% with a 0.20% facility fee. Lenders hold revolving commitments totaling approximately $4.0 billion that mature on May 5, 2022, commitments totaling $20.0 million that mature on May 5, 2021, commitments totaling approximately $247.7 million that mature on May 5, 2020, and commitments totaling $245.0 million that mature on May 5, 2019.

The total amount outstanding under our unsecured revolving credit facility was approximately $956.0 million and $847.0 million as of June 30, 2018 and December 31, 2017, respectively.

Maturities

Maturities of debt outstanding as of June 30, 2018 are as follows (in thousands):


Years ending December 31,
2018	$	777,247
2019		1,203,874
2020		1,232,890
2021		1,685,157
2022		2,078,942
Thereafter		4,100,668
Total	$	11,078,778