XML 64 R52.htm IDEA: XBRL DOCUMENT v3.10.0.1
Income Taxes (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Income Taxes [Abstract]      
Statutory federal rate 21.00%   35.00%
Unrecognized tax benefits $ 0 $ 300,000  
Amount of interest and penalties 0 0  
Cash payments for income taxes $ 6,700,000 $ 16,200,000