Other Income (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Other income
Gain on equity accounted for investments	$ 4,935
Proceeds on disposal of equity investment	6,147
Additional proceeds after escrow conditions	$ 1,020
Escrow release conditions period	5 years
Contingent consideration on sale of equity	$ 1,700