Notes Payable (Pricing Spreads and Facility Fee) (Details) - Credit Facility		12 Months Ended
	Jan. 03, 2018	Dec. 31, 2017
Minimum
Line of Credit Facility [Line Items]
Annual Facility Fee %		0.15%
Maximum
Line of Credit Facility [Line Items]
Leverage Ratio		60.00%
Annual Facility Fee %		0.30%
LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread		1.10%
LIBOR | Minimum
Line of Credit Facility [Line Items]
Applicable % Spread		1.10%
LIBOR | Maximum
Line of Credit Facility [Line Items]
Applicable % Spread		1.45%
Base Rate | Minimum
Line of Credit Facility [Line Items]
Applicable % Spread		0.10%
Base Rate | Maximum
Line of Credit Facility [Line Items]
Applicable % Spread		0.45%
Subsequent Event | ≤ 35%
Line of Credit Facility [Line Items]
Annual Facility Fee %	0.15%
Subsequent Event | ≤ 35% | Maximum
Line of Credit Facility [Line Items]
Leverage Ratio	35.00%
Subsequent Event | ≤ 35% | LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread	1.05%
Subsequent Event | ≤ 35% | Base Rate
Line of Credit Facility [Line Items]
Applicable % Spread	0.10%
Subsequent Event | More than 35% but ≤ 40%
Line of Credit Facility [Line Items]
Annual Facility Fee %	0.20%
Subsequent Event | More than 35% but ≤ 40% | Minimum
Line of Credit Facility [Line Items]
Leverage Ratio	35.00%
Subsequent Event | More than 35% but ≤ 40% | Maximum
Line of Credit Facility [Line Items]
Leverage Ratio	40.00%
Subsequent Event | More than 35% but ≤ 40% | LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread	1.10%
Subsequent Event | More than 35% but ≤ 40% | Base Rate
Line of Credit Facility [Line Items]
Applicable % Spread	0.15%
Subsequent Event | More than 40% but ≤ 45%
Line of Credit Facility [Line Items]
Annual Facility Fee %	0.20%
Subsequent Event | More than 40% but ≤ 45% | Minimum
Line of Credit Facility [Line Items]
Leverage Ratio	40.00%
Subsequent Event | More than 40% but ≤ 45% | Maximum
Line of Credit Facility [Line Items]
Leverage Ratio	45.00%
Subsequent Event | More than 40% but ≤ 45% | LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread	1.20%
Subsequent Event | More than 40% but ≤ 45% | Base Rate
Line of Credit Facility [Line Items]
Applicable % Spread	0.20%
Subsequent Event | More than 45% but ≤ 50%
Line of Credit Facility [Line Items]
Annual Facility Fee %	0.25%
Subsequent Event | More than 45% but ≤ 50% | Minimum
Line of Credit Facility [Line Items]
Leverage Ratio	45.00%
Subsequent Event | More than 45% but ≤ 50% | Maximum
Line of Credit Facility [Line Items]
Leverage Ratio	50.00%
Subsequent Event | More than 45% but ≤ 50% | LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread	1.20%
Subsequent Event | More than 45% but ≤ 50% | Base Rate
Line of Credit Facility [Line Items]
Applicable % Spread	0.20%
Subsequent Event | More than 50%
Line of Credit Facility [Line Items]
Annual Facility Fee %	0.30%
Subsequent Event | More than 50% | Minimum
Line of Credit Facility [Line Items]
Leverage Ratio	50.00%
Subsequent Event | More than 50% | LIBOR
Line of Credit Facility [Line Items]
Applicable % Spread	1.45%
Subsequent Event | More than 50% | Base Rate
Line of Credit Facility [Line Items]
Applicable % Spread	0.45%