Cash Dividends (Details) - $ / shares				3 Months Ended		6 Months Ended	9 Months Ended
	Jun. 07, 2017	Jun. 01, 2017	Mar. 02, 2017	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Jun. 30, 2017	Jun. 30, 2016
Cash Dividends
Cash dividends declared, per share (in dollars per share)	$ 0.70		$ 0.70	$ 0.7000	$ 0.7000	$ 2.1	$ 2.1000	$ 2.0750
Cash dividend paid, per share (in dollars per share)		$ 0.70