Equity Incentive Programs (Deferred Stock Unit Activity) (Details) - Deferred Stock Units (DSUs)	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Units
Outstanding at beginning of period (in shares)	500,961
Granted (in shares)	221,616
Dividend equivalents granted (in shares)	0
Settled (in shares)	(35,186)
Outstanding at end of period (in shares)	687,391
Weighted-Average Grant Date Fair Value Per Share
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 10.69
Granted (in dollars per share) | $ / shares	3.82
Dividend equivalents granted (in dollars per share) | $ / shares	0
Settled (in dollars per share) | $ / shares	11.53
Outstanding at end of period (in dollars per share) | $ / shares	$ 8.36
Number of DSU to class A common share conversion (in shares)	1