Actual and Pro Forma Impact on Net Sales and Operating Loss (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Business Acquisition [Line Items]
Revenue	$ 343,302	$ 404,667	$ 447,684	$ 426,989	$ 305,195	$ 342,904	$ 400,569	$ 355,365	$ 1,622,642	$ 1,404,033	$ 1,310,254
Operating Earnings (Loss)									445,796	385,251	$ 386,667
Kosmos Acquisition [Member] | Pro Forma [Member]
Business Acquisition [Line Items]
Revenue									175,511	7,880
Operating Earnings (Loss)									$ 34,084	$ (6,756)