Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 35,072
Operating lease liabilities	$ 35,125
Cumulative effect of accounting change		$ 700	$ (670)
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		34,900
Operating lease liabilities		34,400
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change		700	$ (670)
Retained Earnings | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change		$ 700