
	December 31,
(in thousands)	2020		2019
Current:
Other borrowings	$	25,415	$	38,728
Long-Term:
Senior Notes
2023 Notes	$	609,764	$	557,185
2024 Notes	496,200		495,240
2028 Notes	595,134		594,502
Other borrowings	8,935		4,812

Borrowings under committed lines of credit	$	—	$	—

In February 2021, we entered into an amended and restated $1.65 billion credit facility which matures in February 2023. This credit facility contains customary financial covenants, including a debt-to-capitalization ratio that cannot exceed 0.65 to 1.00, a limitation on the aggregate amount of debt of the greater of $750 million or €750 million for our subsidiaries, and a minimum liquidity threshold, as defined in the amended credit facility, of $1.5 billion which may be reduced to $1.25 billion

upon the repayment of debt. If this credit facility had been in place as of December 31, 2020, our financial covenants would have limited our further borrowings to approximately $934 million. The credit facility also contains provisions that will require us to provide collateral to secure this facility should we be downgraded to BB by S&P and Ba2 by Moody's, such collateral consisting broadly of our U.S. assets. Borrowings under the facility, which may be denominated in USD, EUR, GBP or CAD, bear interest at a base rate, plus an applicable borrowing margin.

As of December 31, 2020, letters of credit totaling $418 million were outstanding under our predecessor lines of credit, which consisted of a $1.7 billion Revolving Loan and Letter of Credit Facility and a $1.8 billion Revolving Loan and Letter of Credit Facility. There were no borrowings outstanding under these facilities as of December 31, 2020. These credit facilities also contained customary financial and restrictive covenants, including a debt-to-capitalization ratio that could not exceed 0.6 to 1.0.

In August 2018, we issued $600 million of 4.250% Senior Notes due in September 2028 ("2028 Notes") and received proceeds of $595 million. Interest on the 2028 Notes is payable semi-annually in March and September. Prior to June 2028, we may redeem the 2028 Notes at a redemption price equal to 100% of the principal amount, plus a “make whole” premium described in the indenture. After June 2028, the 2028 Notes can be redeemed at par plus accrued interest.

In March 2016, we issued €500 million of 1.750% Senior Notes due in March 2023 ("2023 Notes") and received proceeds of €497 million. Interest on the 2023 Notes is payable annually in March. Prior to December 2022, we may redeem the 2023 Notes at a redemption price equal to 100% of the principal amount, plus a "make whole" premium described in the indenture. After December 2022, the 2023 Notes can be redeemed at par plus accrued interest. Additionally, we may redeem the 2023 Notes at par plus accrued interest if certain changes in U.S. tax laws occur.

In November 2014, we issued $500 million of 3.5% Senior Notes due in December 2024 ("2024 Notes") and received proceeds of $491 million. Interest on the 2024 Notes is payable semi-annually in June and December. Prior to September 2024, we may redeem the 2024 Notes at a redemption price equal to 100% of the principal amount, plus a "make whole" premium described in the indenture. After September 2024, the 2024 Notes can be redeemed at par plus accrued interest.

For all of the Senior Notes, a change of control (as defined by the terms of the respective indentures) could require the company to repay them at 101% of the principal amount, plus accrued interest. We may incur additional indebtedness if we are in compliance with certain restrictive covenants, including restrictions on liens and restrictions on sale and leaseback transactions.

Other borrowings of $34 million and $44 million as of December 31, 2020 and 2019, respectively, primarily represent bank loans and other financing arrangements associated with Stork.

Letters of credit are provided in the ordinary course of business primarily to indemnify our clients if we fail to perform our obligations under our contracts. Surety bonds may be used as an alternative to letters of credit. As of December 31, 2020, letters of credit totaling $862 million were outstanding under uncommitted lines of credit.