CONDENSED CONSOLIDATED STATEMENTS OF COMMON STOCK EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividend declared per share (usd per share)	$ 0.2925	$ 0.2925	$ 0.2925	$ 0.2725	$ 0.2725	$ 0.2725