Condensed Consolidated Statements of Equity (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Statement of Stockholders' Equity [Abstract]
Shares issued on compensation plans	1,084,647	1,779,404
Repurchase of Class A Common shares	561,019	1,181,560
Tax payments related to shares withheld for vested stock and RSUs	$ 5,126	$ 4,035
Cash dividends declared (in dollars per share)	$ 1.03	$ 0
Cash dividends paid (in dollars per share)	$ 1.03	$ 0
Number of shares issued in business acquisition	26,350,993	0