XML 21 R9.htm IDEA: XBRL DOCUMENT v3.10.0.1
CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]    
Dividends paid to public stockholders (per share) $ 0.66 $ 0.63
Dividends paid to affiliate (per share) $ 0.66 $ 0.63