	March 31,			December 31,
	2019			2018
	(In thousands)
Senior credit facility	$	1,070,000		$	750,000
Operating Partnership senior credit facility		2,349,500			2,819,125
MGM China credit facility		2,287,904			2,433,562
$850 million 8.625% senior notes, due 2019		—			850,000
$500 million 5.25% senior notes, due 2020		500,000			500,000
$1,000 million 6.75% senior notes, due 2020		1,000,000			1,000,000
$1,250 million 6.625% senior notes, due 2021		1,250,000			1,250,000
$1,000 million 7.75% senior notes, due 2022		1,000,000			1,000,000
$1,250 million 6% senior notes, due 2023		1,250,000			1,250,000
$1,050 million 5.625% Operating Partnership senior notes, due 2024		1,050,000			1,050,000
$1,000 million 5.75% senior notes, due 2025		1,000,000			1,000,000
$500 million 4.50% Operating Partnership senior notes, due 2026		500,000			500,000
$500 million 4.625% senior notes, due 2026		500,000			500,000
$750 million 5.75% Operating Partnership senior notes, due 2027		750,000			—
$350 million 4.50% Operating Partnership senior notes, due 2028		350,000			350,000
$0.6 million 7% debentures, due 2036		552			552
		14,857,956			15,253,239
Less: Premiums, discounts, and unamortized debt issuance costs, net		(124,579	)		(121,823	)
		14,733,377			15,131,416
Less: Current portion		(2,548	)		(43,411	)
	$	14,730,829		$	15,088,005

Debt due within one year of the March 31, 2019 and December 31, 2018 balance sheets 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 senior credit facilities, with the exception that $3 million and $43 million related to MGM China’s term loan amortization payments in excess of available borrowings under the MGM China revolving credit facility were classified as current at March 31, 2019 and December 31, 2018, respectively.

Senior credit facility. At March 31, 2019, the Company’s senior credit facility consisted of a $750 million term loan A facility and a $1.5 billion revolving facility. At March 31, 2019, $320 million was drawn on the revolving credit facility. At March 31, 2019, the interest rate on the term loan A was 4.75% and the interest rate on the revolving credit facility was 4.66%. The Company was in compliance with its credit facility covenants at March 31, 2019.

Operating Partnership senior credit facility. At March 31, 2019, the Operating Partnership senior credit facility consisted of a $470 million term loan A facility, a $1.79 billion term loan B facility, and a $1.35 billion revolving credit facility. At March 31, 2019, $85 million was drawn on the revolving credit facility. At March 31, 2019, the interest rates on the term loan A facility and the term loan B facility were both 4.5%, and the interest rate on the revolving credit facility was 4.41%. The Operating Partnership was in compliance with its credit facility covenants at March 31, 2019.

The Operating Partnership is party to interest rate swaps to mitigate the interest rate risk inherent in its senior secured term loan B facility. As of March 31, 2019, the Operating Partnership pays a weighted average fixed rate of 1.844% on total notional amount of $1.2 billion and the variable rate received resets monthly to the one-month LIBOR with no minimum floor. In December 2018, the Operating Partnership entered into additional interest rate swaps that have a notional amount of $400 million on which it will pay a fixed rate of 2.735% with the variable rate received resetting monthly to the one-month LIBOR with a floor of 0%. Such interest rate swaps will become effective on December 31, 2019. As of March 31, 2019, and December 31, 2018, the derivative financial instruments have been designated as cash flow hedges and qualify for hedge accounting.

MGM China credit facility. At March 31, 2019, the MGM China credit facility consisted of $1.7 billion of term loans and a $1.0 billion revolving credit facility. MGM China permanently repaid $99 million of the term loan facilities in the three months ended March 31, 2019 in accordance with the scheduled amortization. At March 31, 2019, $599 million was drawn on the revolving credit facility. At March 31, 2019, the interest rates on the term loans and the revolving credit facility were 4.16% and 4.11%, respectively. MGM China was in compliance with its credit facility covenants at March 31, 2019.

Bridge Facility. In connection with the Empire City transaction, the Company borrowed $246 million under a bridge facility, which was subsequently assumed by the Operating Partnership. The Operating Partnership repaid the bridge facility with a combination of cash on hand and a draw on its revolving credit facility, which was subsequently repaid with proceeds from its offering of its 5.75% senior notes due 2027, discussed below.

Senior Notes. In April 2019, the Company issued $1.0 billion in aggregate principal amount of 5.50% senior notes due 2027. The Company primarily used the net proceeds from the offering to fund the purchase of $639 million in aggregate principal amount of its outstanding 6.75% senior notes due 2020 and $233 million in aggregate principal amount of its outstanding 5.25% senior notes due 2020 through cash tender offers.

Operating Partnership senior notes. In January 2019, the Operating Partnership issued $750 million in aggregate principal amount of 5.75% senior notes due 2027.

Fair value of long-term debt. The estimated fair value of the Company’s long-term debt was $15.2 billion and $15.1 billion at March 31, 2019 and December 31, 2018, respectively. Fair value was estimated using quoted market prices for the Company’s senior notes and senior credit facilities.