CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares							3 Months Ended		6 Months Ended
	Jun. 12, 2018	Mar. 14, 2018	Dec. 13, 2017	Sep. 12, 2017	Jun. 15, 2017	Mar. 14, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Stockholders' Equity
Dividends declared per share of common stock	$ 0.40	$ 0.37	$ 0.37	$ 0.37	$ 0.37	$ 0.37	$ 0.40	$ 0.37	$ 0.77	$ 0.74