Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Schedule of Common Stock Outstanding Roll Forward

The changes in shares of Common and Treasury Stock are as follows:

(in thousands)	Common Shares Issued	Treasury Stock Shares	Common Shares Outstanding
Balance as of December 31, 2018	19,067	429	18,638
Net shares issued for stock awards	—	(169)	169
Shares issued to Weichai *	4,050	—	4,050
Balance as of December 31, 2019	23,117	260	22,857
Net shares issued for stock awards	—	(35)	35
Balance as of December 31, 2020	23,117	225	22,892