Credit Agreement (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended
	Apr. 17, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 29, 2019
Line of Credit Facility [Line Items]
Outstanding balance		$ 64,000	$ 82,000
Credit agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 200,000
Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 237,500
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility remaining borrowing capacity		109,000
Revolving Credit Facility [Member] | Credit agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				175,000
Option to increase aggregate amount				225,000
Long-term Debt		39,000
Line of Credit Covenant Trigger		$ 17,500
Line of credit covenant trigger percentage		10.00%
Revolving Credit Facility [Member] | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 212,500
Letter of Credit [Member] | Credit agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 3,800
FILO Term Loan
Line of Credit Facility [Line Items]
Long-term Debt		$ 25,000
FILO Term Loan | Credit agreement
Line of Credit Facility [Line Items]
Face amount				$ 25,000
Minimum [Member] | Revolving Credit Facility [Member] | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Minimum [Member] | Revolving Credit Facility [Member] | Base Rate | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.25%
Minimum [Member] | Revolving Credit Facility [Member] | LIBOR
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.25%
Minimum [Member] | Revolving Credit Facility [Member] | LIBOR | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.50%
Minimum [Member] | FILO Term Loan | Base Rate | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.25%
Minimum [Member] | FILO Term Loan | LIBOR | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.25%
Minimum [Member] | FILO Term Loan | LIBOR | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.75%
Maximum [Member] | Revolving Credit Facility [Member] | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.50%
Maximum [Member] | Revolving Credit Facility [Member] | Base Rate | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.75%
Maximum [Member] | Revolving Credit Facility [Member] | LIBOR
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.75%
Maximum [Member] | Revolving Credit Facility [Member] | LIBOR | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.00%
Maximum [Member] | FILO Term Loan | Base Rate | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.00%
Maximum [Member] | FILO Term Loan | LIBOR | Credit agreement
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		3.00%
Maximum [Member] | FILO Term Loan | LIBOR | Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	4.50%