v3.19.2
Shareholders' Equity - Narrative (Details) - $ / shares
6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Stockholders' Equity Note [Abstract]    
Common stock, shares authorized (in shares) 150,000,000  
Common stock, shares issued (in shares) 88,079,315 87,938,537
Common stock, shares outstanding (in shares) 83,066,135 82,948,577
Preference shares issued (in shares) 18,600,000  
Undesignated shares (in shares) 43,320,685  
Shares repurchased for tax withholding (in shares) 23,220 29,391
Shares repurchased for tax withholding, price per share (in dollars per share) $ 0.78 $ 6.57