Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental non-cash investing and financing activities:
Value of common stock issued in payment of accrued liability	$ 0	$ 0	$ 188
Exercise of stock options by common stock surrender	0	0	5,863
Supplemental cash payment information:
Interest paid	599	2,502	1,851
Income taxes (received, net of payments) paid, net of refunds	$ (699)	$ (139)	$ (10,195)