	June 30,			December 31,
	2021			2020
	(In thousands)
Operating Partnership senior credit facility	$	—		$	10,000
MGM China first revolving credit facility		226,667			770,034
7.75% senior notes, due 2022		1,000,000			1,000,000
6% senior notes, due 2023		1,250,000			1,250,000
5.625% Operating Partnership senior notes, due 2024		1,050,000			1,050,000
5.375% MGM China senior notes, due 2024		750,000			750,000
6.75% senior notes, due 2025		750,000			750,000
5.75% senior notes, due 2025		675,000			675,000
4.625% Operating Partnership senior notes, due 2025		800,000			800,000
5.25% MGM China senior notes, due 2025		500,000			500,000
5.875% MGM China senior notes, due 2026		750,000			750,000
4.5% Operating Partnership senior notes, due 2026		500,000			500,000
4.625% senior notes, due 2026		400,000			400,000
5.75% Operating Partnership senior notes, due 2027		750,000			750,000
5.5% senior notes, due 2027		675,000			675,000
4.75% MGM China senior notes, due 2027		750,000			—
4.5% Operating Partnership senior notes, due 2028		350,000			350,000
4.75% senior notes, due 2028		750,000			750,000
3.875% Operating Partnership senior notes, due 2029		750,000			750,000
7% debentures, due 2036		552			552
		12,677,219			12,480,586
Less: Premiums, discounts, and unamortized debt issuance costs, net		(102,280	)		(103,902	)
	$	12,574,939		$	12,376,684

Debt due within one year of the June 30, 2021 balance sheet was classified as long-term as the Company had both the intent and ability to refinance current maturities on a long-term basis under its revolving credit facilities.

Senior credit facility. At June 30, 2021, the Company’s senior credit facility consisted of a $1.5 billion revolving facility. At June 30, 2021, no amounts were drawn on the revolving credit facility.

In February 2021, the Company amended its credit facility to extend the covenant relief period provided under the previous amendment related to its financial maintenance covenants through the earlier of (x) the day immediately following the date the Company delivers to the administrative agent a compliance certificate with respect to the quarter ending June 30, 2022 and (y) the date the Company delivers to the administrative agent an irrevocable notice terminating the covenant relief period, and to adjust the required leverage and interest coverage levels for the covenant when it is reimposed at the end of the waiver period. In addition, in connection with the February 2021 amendment, the Company agreed to an increase of the liquidity test such that the Company’s borrower group (as defined in the credit agreement) is required to maintain a minimum liquidity level of not less than $1.0 billion (including unrestricted cash, cash equivalents and availability under the revolving credit facility), tested at the end of each month during the covenant relief period.

The Company’s senior credit facility contains customary representations and warranties, events of default and positive and negative covenants. The Company was in compliance with its applicable covenants at June 30, 2021.

Operating Partnership senior credit facility and bridge facility. At June 30, 2021, the Operating Partnership senior credit facility consisted of a $1.35 billion revolving credit facility. At June 30, 2021, no amounts were drawn on the revolving credit facility. The Operating Partnership was in compliance with its revolving credit facility covenants at June 30, 2021.

The Operating Partnership is party to interest rate swaps to mitigate the effects of interest rate volatility inherent in its variable rate debt as well as forecasted debt issuances. As of June 30, 2021, the Operating Partnership has currently effective interest rate swap agreements on which it pays a weighted average fixed rate of 1.783% on total notional amount of $700 million. The Operating Partnership has an additional $900 million total notional amount of forward starting interest rate swaps that are not currently effective. The fair value of interest rate swaps designated as cash flow hedges was $33 million, recorded as a long-term liability, as of June 30, 2021, and $41 million, with $1 million recorded as a current liability and $40 million recorded as a long-term liability, as of December 31, 2020. The fair value of interest rate swaps not designated as cash flow hedges was $38 million, with $11 million recorded as a current liability and $27 million recorded as a long-term liability, as of June 30, 2021, and $78 million, with $31 million recorded as a current liability and $47 million recorded as a long-term liability, as of December 31, 2020. Interest rate swaps in a current liability position are recorded within “Other accrued expenses” and those in a long-term liability position are recorded within “Other long-term liabilities” on the consolidated balance sheets.

MGM China first revolving credit facility. At June 30, 2021, the MGM China first revolving credit facility consisted of a $1.25 billion unsecured revolving credit facility. At June 30, 2021, $227 million was drawn on the MGM China first revolving credit facility and the weighted average interest rate was 2.84%.

The MGM China first revolving credit facility contains customary representations and warranties, events of default, and positive, negative and financial covenants, including that MGM China maintains compliance with a maximum leverage ratio and a minimum interest coverage ratio. In February 2021, MGM China amended its credit agreement to provide for a waiver of its maximum leverage ratio and its minimum interest coverage ratio through the fourth quarter of 2022. MGM China was in compliance with its applicable MGM China first revolving credit facility covenants at June 30, 2021.

MGM China second revolving credit facility. At June 30, 2021, the MGM China second revolving credit facility consisted of a $400 million unsecured revolving credit facility with an option to increase the amount of the facility up to $500 million, subject to certain conditions. Draws will be subject to satisfaction of certain conditions precedent, including evidence that the MGM China first revolving credit facility has been fully drawn. At June 30, 2021, no amounts were drawn on the MGM China second revolving credit facility.

The MGM China second revolving credit facility contains customary representations and warranties, events of default, and positive, negative and financial covenants, including that MGM China maintains compliance with a maximum leverage ratio and a minimum interest coverage ratio beginning in the third quarter of 2021. In February 2021, MGM China amended its credit agreement to provide for a waiver of its maximum leverage ratio and its minimum interest coverage ratio through the fourth quarter of 2022. MGM China was in compliance with its applicable MGM China second revolving credit facility covenants at June 30, 2021.

MGM China senior notes. In March 2021, MGM China issued $750 million in aggregate principal amount of 4.75% senior notes due 2027 at an issue price of 99.97%.

Fair value of long-term debt. The estimated fair value of the Company’s long-term debt was $13.4 billion and $13.2 billion at June 30, 2021 and December 31, 2020, respectively. Fair value was estimated using quoted market prices for the Company’s senior notes and credit facilities.