Stockholders' Equity - Dividends Declared (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	$ 0.61	$ 0.55	$ 1.89	$ 2.14
Quarterly
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	0.61	0.55	1.29	1.11
Special Annual
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	$ 0	$ 0	$ 0.60	$ 1.03