Summary of Significant Accounting Policies - Reconciliation of Restructuring Liabilities (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Charged to restructuring costs		$ 3,571	$ 2,758	$ 1,026
Cost Optimization Project
Restructuring Reserve [Roll Forward]
Direct write offs related to abandoned locations			400
Cost Optimization Project | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 556	556	87	325
Charged to restructuring costs			1,600	522
Payments			(1,131)	(760)
Balance at end of period			556	87
Cost Optimization Project | Lease-Related Exit Costs
Restructuring Cost and Reserve [Line Items]
ASC 842 lease reclassification	300
Restructuring Reserve [Roll Forward]
Balance at beginning of period	390	390	441	273
Charged to restructuring costs			184	504
Payments			(235)	(336)
Balance at end of period			390	$ 441
Cost Optimization Project | Other costs
Restructuring Reserve [Roll Forward]
Charged to restructuring costs			500
2019 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges, Reduction Of Lease Footprint		200
2019 Restructuring Plan [Member] | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Charged to restructuring costs		1,870
Payments		(2,040)
Balance at end of period		386
2019 Restructuring Plan [Member] | Lease-Related Exit Costs
Restructuring Reserve [Roll Forward]
Charged to restructuring costs		1,311
Payments		(215)
Balance at end of period		1,223
2019 Restructuring Plan [Member] | Other costs
Restructuring Reserve [Roll Forward]
Charged to restructuring costs		100
ASU 2016-02 | Cost Optimization Project | Lease-Related Exit Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 127	$ 127
Balance at end of period			$ 127