Subsequent Events (Details) - $ / shares		3 Months Ended								12 Months Ended
	Jan. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Subsequent Events
Quarterly cash dividend declared on common stock (in dollars per share)		$ 0.73	$ 0.22	$ 0.32	$ 0.22	$ 0.42	$ 0.22	$ 0.30	$ 0.20	$ 1.49	$ 1.14
Subsequent event
Subsequent Events
Quarterly cash dividend declared on common stock (in dollars per share)	$ 0.23