Other Long-Term Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Cash surrender value of corporate-owned life insurance policies	$ 3,596		$ 3,846
Deferred commissions, net of current portion	15,530	$ 12,200	6,803
Restricted cash	661		3,333
Prepaid expenses, deposits and other	3,212		1,384
Total other long-term assets	$ 22,999	$ 20,689	$ 15,366