Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Cash surrender value of corporate-owned life insurance policies	$ 4,018		$ 3,596
Deferred commissions	16,597		15,530
Restricted cash	660		661
Operating lease assets	10,770
Prepaid expenses, deposits and other	3,549		3,212
Total other long-term assets	$ 35,594	$ 35,482	$ 22,999