Basis of Presentation and Significant Accounting Policies - New Guidance (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease, right-of-use asset	$ 27,653		$ 0
Operating lease, liability	$ 28,541
ASU 2016-02
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease, right-of-use asset		$ 28,000
Operating lease, liability		$ 28,000