Commitments and Contingencies Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contract settlement	$ 12,700	$ 28,900	$ 2,083	$ 0
contingent consideration gross			$ 225,000	$ 225,000