Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Tax benefit related to delivery of Class A Common Stock in connection with share-based incentive compensation	$ 448	$ 13,138	$ 4,783
Tax benefit related to delivery of Class A Common Stock	$ 1,074
Common stock, shares issued	129,766,091	129,766,091
Class A Common Stock [Member]
Common stock, shares issued	129,766,091	129,766,091	129,766,091