Revenue from Contracts with Customers - Revenue by Customer or Customer Group (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 27, 2020	Sep. 29, 2019
Entity Wide Revenue Major Customer [Line Items]
Revenue	$ 126,234	$ 119,962
General Motors Company
Entity Wide Revenue Major Customer [Line Items]
Revenue	37,756	33,838
Fiat Chrysler Automobiles
Entity Wide Revenue Major Customer [Line Items]
Revenue	25,083	25,482
Ford Motor Company
Entity Wide Revenue Major Customer [Line Items]
Revenue	15,846	15,812
Commercial and Other OEM Customers
Entity Wide Revenue Major Customer [Line Items]
Revenue	21,434	21,346
Tier 1 Customers
Entity Wide Revenue Major Customer [Line Items]
Revenue	17,495	17,747
Hyundai / Kia
Entity Wide Revenue Major Customer [Line Items]
Revenue	$ 8,620	$ 5,737