Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 Rig Hotel State Segment mi
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	5
Number of individual operating subsidiaries | Segment	4
Diamond Offshore [Member]
Segment Reporting Information [Line Items]
Number of offshore rigs owned | Rig	17
Diamond Offshore [Member] | Drillship [Member]
Segment Reporting Information [Line Items]
Number of offshore rigs owned | Rig	4
Diamond Offshore [Member] | Semisubmersible [Member]
Segment Reporting Information [Line Items]
Number of offshore rigs owned | Rig	13
Boardwalk Pipeline [Member]
Segment Reporting Information [Line Items]
Miles of natural gas and NGL pipeline | mi	14,230
Number of states having natural gas storage facilities | State	4
Loews Hotels And Co [Member]
Segment Reporting Information [Line Items]
Total number of hotels owned and/or operated | Hotel	24
Loews Hotels And Co [Member] | United States [Member]
Segment Reporting Information [Line Items]
Number of hotels | Hotel	22
Loews Hotels And Co [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Number of hotels | Hotel	2