Statements of Shareholders' Equity (unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Per share amount of cash dividends declared (in dollars per share)	$ 0.14	$ 0.135	$ 0.415	$ 0.40