Related Party Transactions (Details 4) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Carrying value of non-controlling interest, Beginning Balance	$ 46,429
Net and comprehensive income for the period	48	$ (3,646)
Carrying value of non-controlling interest, Ending Balance	46,458		$ 46,429
Gauss LLC [Member] | Permanent Non-controlling Interest [Member]
Related Party Transaction [Line Items]
Carrying value of non-controlling interest, Beginning Balance	46,429	36,321	36,321
Capital contribution			10,000
Net and comprehensive income for the period	29		108
Carrying value of non-controlling interest, Ending Balance	46,458		46,429
Gauss LLC [Member] | Temporary Non-controlling Interest [Member]
Related Party Transaction [Line Items]
Carrying value of non-controlling interest, Beginning Balance	24,286	$ 24,214	24,214
Capital contribution			0
Net and comprehensive income for the period	19		72
Carrying value of non-controlling interest, Ending Balance	$ 24,305		$ 24,286