Fair Value Measurements and Derivative Instruments (Nonrecurring) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Grand Bahamas Shipyard Ltd.
Liabilities:
Equity method investment impairment	$ 30,100,000
Not Primary Beneficiary | Grand Bahamas Shipyard Ltd.
Liabilities:
Net book value of equity method investment	$ 0
Fair Value, Measurements, Nonrecurring
Liabilities:
Equity method investment impairment		$ 39,735,000
Fair Value, Measurements, Nonrecurring | Level 1
Assets:
Cash and cash equivalents		3,684,474,000	$ 243,738,000
Total Assets		3,684,474,000	243,738,000
Liabilities:
Long-term debt (including current portion of long-term debt)		0	0
Total Liabilities		0	0
Fair Value, Measurements, Nonrecurring | Level 2
Assets:
Cash and cash equivalents		0	0
Total Assets		0	0
Liabilities:
Long-term debt (including current portion of long-term debt)		20,981,040,000	10,059,055,000
Total Liabilities		20,981,040,000	10,059,055,000
Fair Value, Measurements, Nonrecurring | Level 3
Assets:
Cash and cash equivalents		0	0
Total Assets		0	0
Liabilities:
Long-term debt (including current portion of long-term debt)		0	0
Total Liabilities		0	0
Total Carrying Amount | Fair Value, Measurements, Nonrecurring
Assets:
Cash and cash equivalents		3,684,474,000	243,738,000
Total Assets		3,684,474,000	243,738,000
Liabilities:
Long-term debt (including current portion of long-term debt)		18,706,359,000	9,370,438,000
Total Liabilities		18,706,359,000	9,370,438,000
Total Fair Value | Fair Value, Measurements, Nonrecurring
Assets:
Cash and cash equivalents		3,684,474,000	243,738,000
Total Assets		3,684,474,000	243,738,000
Liabilities:
Long-term debt (including current portion of long-term debt)		20,981,040,000	10,059,055,000
Total Liabilities		$ 20,981,040,000	$ 10,059,055,000