XML 44 R32.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair value measurement - LTIP Investments Carried at Fair Value by Category on Condensed Consolidated and Combined Balance Sheets in Accordance with Valuation Hierarchy (Details) - Fair Value Recurring - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Assets:    
Total investments at fair value $ 2,293 $ 3,259
Mutual Funds    
Assets:    
Fair value measurements, Assets 1,687 2,228
Fixed Income Fund    
Assets:    
Fair value measurements, Assets 606 1,031
Level 1 | Mutual Funds    
Assets:    
Fair value measurements, Assets $ 1,687 $ 2,228