Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Domestic and foreign components of income before income taxes
United States	$ 107,639	$ 111,002	$ 105,555
Foreign	10,270	2,356	(272)
Income before provision for income taxes	117,909	113,358	105,283
Current provision (benefit)
Federal	12,513	3,405	21,509
State	4,398	4,536	3,371
Foreign	2,954	674	(188)
Total	19,865	8,615	24,692
Deferred provision (benefit)
Federal	12,283	14,535	1,958
State	1,940	2,120	1,219
Foreign	(276)	(139)	(36)
Total	13,947	16,516	3,141
Change in valuation allowance		634	600
Total	$ 33,812	$ 25,765	$ 28,433
Reconciliation of income tax expense compared to the amount of income tax expense that would result by applying U.S. federal statutory income tax rate to pre-tax income
Federal statutory income tax rate (as a percent)	21.00%	21.00%	35.00%
Impact of U.S tax reform		1.10%	(9.30%)
State taxes, net of federal income tax impact (as a percent)	4.40%	5.10%	2.90%
Tax credits	(1.70%)	(5.30%)
Income taxed at rates greater than U.S.	1.10%	0.40%	(0.20%)
Domestic production activities deduction (as a percent)			(2.30%)
Nondeductible meals & entertainment (as a percent)	3.00%	2.90%	2.80%
Nondeductible compensation	0.70%	0.20%	0.10%
Other items (as a percent)	0.60%	(0.40%)	(0.80%)
Effective tax rate excluding the impact of the Tax Act and income attributable to noncontrolling interests (as a percent)	29.10%	25.00%	28.20%
Impact of income from noncontrolling interests on effective tax rate (as a percent)	(0.40%)	(2.30%)	(1.20%)
Effective tax rate (as a percent)	28.70%	22.70%	27.00%
TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxLiabilityProvisionalIncomeTaxBenefit			$ 9,400
Additional income tax related to complete accounting of Tax Act		$ 1,100
Additional income tax related to foreign tax credits		600
Additional income tax related to depreciation		500
Deferred tax assets:
Accrued compensation	$ 3,705	4,999
Accrued workers compensation	9,939	10,309
Net operating losses	40,919	34,615
Disallowed interest	533	1,908
Capital loss carryforward	10,126	10,796
Deferred rent	126	1,552
Lease liabilities	62,023
Insurance reserves	3,146	3,737
Loss reserves	2,276	2,064
Tax credit	825	1,505
State income taxes	1,193	1,045
Other	3,436	2,146
Total deferred tax assets	138,247	74,676
Deferred tax liabilities
Depreciation and amortization	(63,824)	(56,670)
Prepaid expense and other	(1,839)	(777)
Lease assets	(61,417)
Total deferred tax liabilities	(127,080)	(57,447)
Valuation allowance	(27,886)	(23,938)
Net deferred tax liabilities	$ (16,719)	(6,709)
Expiration period for state net operating loss carryforwards (in years)	20 years
Valuation allowance excluding foreign tax credit	$ 27,900
Change in unrecognized tax benefits	$ (600)
Minimum period of statute of limitations of state and foreign jurisdictions	3 years
Maximum period of statute of limitations of state and foreign jurisdictions	5 years
Reconciliation and aggregate changes for unrecognized tax benefits
Beginning balance	$ 1,330	592
Increases in balances for tax positions taken during the current year	298	146	592
Increases in balances for tax positions taken during prior years	19	2,666
Settlements and effective settlements with tax authorities	(649)	(1,979)
Lapse of statute of limitations	(151)	(95)
Total	847	$ 1,330	$ 592
Capital loss carryforward
Deferred tax liabilities
Tax credit carryforward	10,100
General tax credit carryforward
Deferred tax liabilities
Tax credit carryforward	800
ITC
Deferred tax assets:
Claimed tax credits	600
Foreign tax credits
Deferred tax liabilities
Tax credit carryforward	600
Federal
Deferred tax liabilities
Net operating loss carryforward	21,300
State
Deferred tax liabilities
Net operating loss carryforward	15,900
AUSTRALIA | Foreign
Deferred tax liabilities
Net operating loss carryforward	2,600
Canada
Reconciliation of income tax expense compared to the amount of income tax expense that would result by applying U.S. federal statutory income tax rate to pre-tax income
Federal statutory income tax rate (as a percent)		26.50%	26.50%	26.50%
Canada | Foreign
Deferred tax liabilities
Net operating loss carryforward	1,100
Maximum
Deferred tax liabilities
Reasonably possible decrease in unrecognized tax benefits	$ 200