CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Stockholders Equity [Abstract]
Cash dividends declared per common share (in dollars per share)	$ 0.28	$ 0.27	$ 0.56	$ 0.54