Stock-based Compensation Expense Activity in Performance Unit Awards (Details) - Performance Unit Awards	12 Months Ended
	Dec. 31, 2021 $ / shares shares
Shares
Nonvested, beginning of period (in shares) | shares	226,808
Granted (in shares) | shares	63,648
Vested (in shares) | shares	(37,783)
Forfeited (in shares) | shares	(27,770)
Nonvested, end of period (in shares) | shares	224,903
Weighted Average Grant Date Fair Value
Nonvested, beginning of period (in dollars per share) | $ / shares	$ 116.54
Granted (in dollars per share) | $ / shares	157.21
Vested (in dollars per share) | $ / shares	155.65
Forfeited (in dollars per share) | $ / shares	117.27
Nonvested, end of period (in dollars per share) | $ / shares	$ 121.39