Condensed Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Dividends declared per share of common stock	$ 0.14	$ 0.18	$ 0.42	$ 0.54
Dividends declared and paid per share of common stock	$ 0.14	$ 0.18	$ 0.42	$ 0.54
Repurchase of Class A common stock, shares		8,263	233,172	734,802
Forfeitures of restricted Class A common stock, shares		49,189	22,000	193,819
Class A Common Stock [Member]
Equity-based compensation, shares	61,851	82,345	383,357	464,019
Grant of exchangeability and redemption of limited partnership interests, shares	4,001,618	2,474,658	9,701,674	9,949,679
Issuance of Class A common stock (net of costs), shares	53,810	23,767	162,237	25,975,240
Repurchase of Class A common stock, shares	0	8,263	233,172	734,802
Forfeiture of Class A common stock, shares	22,046		22,046
Issuance of Class A common stock and RSUs for acquisitions, shares	348,797	78,678	848,246	1,083,150
Forfeitures of restricted Class A common stock, shares	22,046	49,189	22,046	193,819
Class A Common Stock [Member] | Smith Mack [Member]
Issuance of Class A common stock and RSUs for acquisitions, shares	348,797	78,678	848,246	1,083,150
Class A Common Stock [Member] | Partnership Units [Member]
Redemption of FPUs	37,126	17,868	42,181	98,991