XML 137 R119.htm IDEA: XBRL DOCUMENT v3.8.0.1
Related Party Transactions (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 13, 2017
Aug. 18, 2017
Dec. 31, 2017
Dec. 31, 2015
Related Party Transaction [Line Items]        
Treasury stock acquired, shares     574,054 1,927,665
Average cost per share (in usd per share)     $ 24.35 $ 23.34
Payments for repurchase of equity     $ 14.0 $ 45.0
Board of Directors Chairman [Member] | Share Repurchase [Member]        
Related Party Transaction [Line Items]        
Treasury stock acquired, shares   100,000    
Average cost per share (in usd per share)   $ 23.85    
Payments for repurchase of equity   $ 2.4    
Purchases from related party $ 0.3