Summary of Quarterly Financial Information - Summary of Unaudited Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Sales	$ 1,330,732	$ 1,353,998	$ 1,258,565	$ 1,276,756	$ 1,080,798	$ 1,176,395	$ 1,134,797	$ 1,250,078	$ 5,220,051	$ 4,642,068	$ 4,164,160
Gross profit	637,749	653,064	609,835	590,509	515,678	563,866	560,957	583,104	2,491,157	2,223,605	1,938,889
Net earnings (loss)	82,501	121,734	91,998	131,019	67,105	106,051	60,859	137,258	427,252	371,273	235,104
Net earnings (loss) attributable to Skechers U.S.A., Inc.	$ 59,532	$ 103,090	$ 75,180	$ 108,758	$ 47,377	$ 90,728	$ 45,284	$ 117,652	$ 346,560	$ 301,041	$ 179,190
Net earnings (loss) per share:
Basic	$ 0.39	$ 0.67	$ 0.49	$ 0.71	$ 0.31	$ 0.58	$ 0.29	$ 0.21	$ 2.26	$ 1.93	$ 1.15
Diluted	$ 0.39	$ 0.67	$ 0.49	$ 0.71	$ 0.31	$ 0.58	$ 0.29	$ 0.21	$ 2.25	$ 1.92	$ 1.14