Stockholders' Equity (Details)	3 Months Ended
	Mar. 31, 2018 votes $ / shares shares	Mar. 31, 2017 $ / shares	Dec. 31, 2017 $ / shares shares
Class of Stock [Line Items]
Common stock, shares outstanding	76,987,641		75,569,845
Dividends declared per Class A common share (in dollars per share) | $ / shares	$ 1.39	$ 0.96
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares authorized	500,000,000		500,000,000
Common stock, shares outstanding	53,483,634		50,463,126
Common stock votes per share | votes	1
Common stock, par value per share | $ / shares	$ 0.01		$ 0.01
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares authorized	200,000,000		200,000,000
Common stock, shares outstanding	9,707,506		11,922,192
Common stock votes per share | votes	1
Common stock, par value per share | $ / shares	$ 0.01		$ 0.01
Class C Common Stock
Class of Stock [Line Items]
Common stock, shares authorized	400,000,000		400,000,000
Common stock, shares outstanding	13,796,501		13,184,527
Common stock votes per share | votes	1
Common stock, par value per share | $ / shares	$ 0.01		$ 0.01
Restricted Stock
Class of Stock [Line Items]
Unvested - Number of awards	5,161,088		4,013,986
Restricted Stock | General Partnership Units
Class of Stock [Line Items]
Unvested - Number of awards	5,057,963
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Outstanding - Number of awards	246,581		218,089
Quarterly Cash Dividend
Class of Stock [Line Items]
Dividends declared per Class A common share (in dollars per share) | $ / shares	$ 0.60	0.60
Special Annual Dividend
Class of Stock [Line Items]
Dividends declared per Class A common share (in dollars per share) | $ / shares	$ 0.79	$ 0.36