Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Deferred compensation plan	$ 27,343	$ 25,672
Supplemental executive retirement plan	15,250	15,035
Operating lease liabilities	11,452	0
Other long-term liabilities	1,294	2,802
Total Other long-term liabilities	$ 55,339	$ 43,509