Basis of Presentation - Adjustments for Adoption (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset	$ 5,488		$ 0
Operating lease, liability	5,549
Other long-term assets	16,553	$ 14,949	7,993
Other liabilities		53,143	50,058
Other long-term liabilities	$ 5,449	4,811	$ 940
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset		7,000
Operating lease, liability		7,000
Other long-term assets		6,956
Other liabilities		3,085
Other long-term liabilities		$ 3,871