Borrowings and Credit Facilities (Textuals) (Details) - USD ($)				1 Months Ended	3 Months Ended
	Dec. 14, 2015	Jul. 29, 2014	Oct. 12, 2011	Nov. 30, 2006	Apr. 27, 2018	Jan. 27, 2017	Oct. 28, 2016	Jan. 29, 2016	Jun. 16, 2011
Line of Credit Facility [Line Items]
Interest expense recognized for direct borrowings under the Credit Agreement						$ 12,610,000		$ 12,923,000
Repayments of Term Loan						(9,375,000)		(4,687,000)
Term Loan due 2019
Line of Credit Facility [Line Items]
Principal amount		$ 375,000,000
Term loan outstanding		375,000,000
Repayments of Term Loan						$ (9,400,000)		(4,700,000)
Prior Term Loan
Line of Credit Facility [Line Items]
Principal amount									$ 500,000,000.0
5.125% Senior Notes due 2021
Line of Credit Facility [Line Items]
Principal amount			$ 500,000,000.0
Interest rate (as percent)			5.125%			5.125%	5.125%
Percentage of principal amount of notes to be redeemed at company's option (as percent)			100.00%
6.625% Senior Notes due 2036
Line of Credit Facility [Line Items]
Principal amount				$ 150,000,000.0
Interest rate (as percent)				6.625%		6.625%	6.625%
Percentage of principal amount of notes to be redeemed at company's option (as percent)				100.00%
Treasury Rate | 5.125% Senior Notes due 2021
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)			0.50%
Treasury Rate | 6.625% Senior Notes due 2036
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)				0.375%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum consolidated leverage ratio		3.00					$ 4.5
Unsecured revolving credit facility maximum borrowing capacity	$ 850,000,000.000	1,000,000,000.0
Letter of credit sublimit	$ 500,000,000
Priority debt limit as a percentage of consolidated net worth (as percent)	10.00%
Cash dividend covenant limit	$ 25,000,000.0
Line of credit additional borrowing capacity		$ 250,000,000
Line of credit amount outstanding						$ 0
Interest expense recognized for direct borrowings under the Credit Agreement						0		$ 500,000
Letters of credit outstanding						125,200,000
Available borrowing capacity						$ 724,800,000
Revolving Credit Facility | Eurodollar Interest Period One
Line of Credit Facility [Line Items]
Interest period		7 days
Revolving Credit Facility | Eurodollar Interest Period Two
Line of Credit Facility [Line Items]
Interest period		1 month
Revolving Credit Facility | Eurodollar Interest Period Three
Line of Credit Facility [Line Items]
Interest period		2 months
Revolving Credit Facility | Eurodollar Interest Period Four
Line of Credit Facility [Line Items]
Interest period		3 months
Revolving Credit Facility | Eurodollar Interest Period Five
Line of Credit Facility [Line Items]
Interest period		6 months
Revolving Credit Facility | Eurodollar Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)		1.00%
Revolving Credit Facility | Federal Funds Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)		0.50%
Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Line of credit commitment fee percentage on unused capacity (as percent)		0.09%
Revolving Credit Facility | Minimum | Eurodollar Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)		1.00%
Revolving Credit Facility | Maximum
Line of Credit Facility [Line Items]
Line of credit commitment fee percentage on unused capacity (as percent)		0.30%
Revolving Credit Facility | Maximum | Eurodollar Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)		2.00%
Forecast | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum consolidated leverage ratio					$ 3.0