Stockholders' Equity (Details) - $ / shares					6 Months Ended
	May 20, 2020	Mar. 05, 2020	May 16, 2019	Mar. 29, 2019	Jun. 30, 2020	Jun. 30, 2019
Stockholders' Equity
Dividends Payable, Date of Record			Jun. 28, 2019	Mar. 29, 2019
Common Stock dividend declared (per share)			$ 1.22	$ 1.10		$ 2.32
Common Stock
Stockholders' Equity
Dividends Payable, Date of Record	Jun. 30, 2020	Mar. 31, 2020
Common Stock dividend declared (per share)	$ 1.22	$ 1.22			$ 2.44