Property and Equipment - Schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 560,555	$ 510,621
Accumulated depreciation	322,628	300,626
Net property and equipment	237,927	209,995
Land and improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	47,054	47,405
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	149,159	139,685
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	346,850	308,873
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 17,492	$ 14,658