Summary of Significant Accounting Policies - Noncontrolling Interests (Details) $ in Thousands, $ in Millions			1 Months Ended		3 Months Ended
	Sep. 01, 2018 USD ($) shares	Sep. 01, 2018 TWD ($) shares	Mar. 31, 2020 shares	Dec. 31, 2018 shares	Nov. 30, 2018 USD ($)	May 31, 2020 shares	Aug. 31, 2019 shares	Aug. 31, 2018 shares
Minority Interest [Line Items]
Common stock, shares issued						4,006,000	3,594,000
Taiwan Bandaoti Zhaoming Co., Ltd.
Minority Interest [Line Items]
Noncontrolling interest (as percentage)	3.31%	3.31%				3.25%		0.00%
Taiwan Bandaoti Zhaoming Co., Ltd.
Minority Interest [Line Items]
Common stock issued during period, shares	414,000	414,000
Common stock, shares issued	12,501,715	12,501,715						12,087,715
Common stock issued during period, value	$ 176	$ 5.4			$ 176
Taiwan SemiLEDs | Taiwan Bandaoti Zhaoming Co., Ltd.
Minority Interest [Line Items]
Common shares purchased form non-controlling interests			5,000	3,000