XML 21 R7.htm IDEA: XBRL DOCUMENT v3.10.0.1
CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - $ / shares
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Dec. 31, 2016
Common stock, par value (in usd per share) $ 0.001   $ 0.001  
Treasury stock (in shares) 24,672,932   24,721,372  
Common stock        
Common stock, par value (in usd per share)     $ 0.001 $ 0.001
Options exercised (in shares) 107,148 127,774    
Conversion of common stock units (in shares) 30,368 15,981    
Conversion of restricted stock units (in shares) 163,835 280,341    
Retained earnings        
Cash dividends (in usd per share) $ 0.57 $ 0.55    
Treasury stock, at cost        
Treasury stock (in shares) 24,723,533 24,672,932 24,721,372 24,672,932
Treasury stock, acquisitions (in shares) 2,161 0