Details	6 Months Ended
	Jun. 30, 2019
Cover page.
Entity Current Reporting Status	Yes
Document Information [Line Items]
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Security Exchange Name	NYSE
Entity Incorporation, State or Country Code	DE
Document Transition Report	false
Title of 12(b) Security	Class A Common Stock, par value $0.01 per share
Entity Small Business	false
Entity Emerging Growth Company	false