Income Taxes Income Taxes (Deferred Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets related to:
Accounts receivable	$ 2,162	$ 2,278
Inventory	4,694	2,631
Accrued compensation	5,531	6,783
Insurance reserves	12,447	11,545
Stock-based compensation	4,183	3,399
Restructuring reserves	444	325
Other accrued liabilities	1,170	1,514
Federal net operating loss carryforward	15,326	16,349
State net operating loss carryforward	2,663	3,882
Operating llease liabilities	34,529	0
Other	707	1,915
Deferred tax assets, gross	83,856	50,621
Valuation allowance	(145)	(145)	$ (145)	$ (125)
Total deferred tax assets	83,711	50,476
Deferred tax liabilities related to:
Goodwill and intangibles	(22,696)	(21,946)
Property and equipment	(41,364)	(29,684)
Operating lease assets	(32,873)	0
Other assets	(1,973)	(1,880)
Total deferred tax liabilities	98,906	53,510
Net deferred tax (liability) asset	$ (15,195)	$ (3,034)