CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Common Class A
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock shares issued (in shares)	133,867,621	137,180,213
Common stock shares outstanding (in shares)	133,867,621	137,180,213
Common Class B
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock shares issued (in shares)	4,045,199	4,045,199
Common stock shares outstanding (in shares)	4,045,199	4,045,199
Common Class C
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock shares issued (in shares)	0	0
Common stock shares outstanding (in shares)	0	0