v3.7.0.1
Stockholders' Equity ASR Activity (Details) - Common Class A [Member]
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended
Mar. 31, 2017
USD ($)
$ / shares
shares
Equity, Class of Treasury Stock [Line Items]  
Treasury stock, value $ 150,000
March 2017 ASR [Member]  
Equity, Class of Treasury Stock [Line Items]  
Treasury stock, shares acquired | shares 1,326
Treasury stock, value $ 50,000
April 2016 ASR [Member]  
Equity, Class of Treasury Stock [Line Items]  
Treasury stock, shares acquired | shares 2,219
Treasury stock acquired, average cost per share (in USD per share) | $ / shares $ 22.54
Treasury stock, value $ 50,000
September 2015 ASR [Member]  
Equity, Class of Treasury Stock [Line Items]  
Treasury stock, shares acquired | shares 2,342
Treasury stock acquired, average cost per share (in USD per share) | $ / shares $ 17.08
Treasury stock, value $ 40,000