Debt (Details)						3 Months Ended
	Mar. 26, 2020 CAD ($) extension	Sep. 24, 2019	Sep. 23, 2019	Dec. 04, 2018	Dec. 03, 2018	Mar. 31, 2020 CAD ($)	Mar. 31, 2020 USD ($)	Mar. 26, 2020 USD ($) extension	Dec. 31, 2019 USD ($)	Apr. 26, 2019 USD ($)	Nov. 06, 2018 USD ($)	May 01, 2013 USD ($)
Mortgages, Senior Notes and Term Loans
Debt Instrument [Line Items]
Carrying Amount							$ 1,833,845,000		$ 1,708,443,000
Estimated Fair Value							1,851,858,000		1,783,463,000
Less: deferred financing costs							(14,976,000)		(12,996,000)
Total indebtedness, net of unamortized deferred financing costs							1,818,869,000		1,695,447,000
Mortgage Loans | 2013 Mortgage Loans
Debt Instrument [Line Items]
Carrying Amount							281,770,000		283,443,000
Estimated Fair Value							$ 282,160,000		287,463,000
Face amount of debt												$ 322,000,000.0
Mortgage Loans | Senior note
Debt Instrument [Line Items]
Contractual Interest Rate						3.81%	3.81%
Effective Interest Rate as of March 31, 2020						4.14%	4.14%
Carrying Amount							$ 179,770,000		181,443,000
Estimated Fair Value							$ 180,670,000		184,618,000
Mortgage Loans | Mezzanine A
Debt Instrument [Line Items]
Contractual Interest Rate						7.38%	7.38%
Effective Interest Rate as of March 31, 2020						7.55%	7.55%
Carrying Amount							$ 70,000,000		70,000,000
Estimated Fair Value							$ 69,650,000		70,525,000
Mortgage Loans | Mezzanine B
Debt Instrument [Line Items]
Contractual Interest Rate						11.50%	11.50%
Effective Interest Rate as of March 31, 2020						11.75%	11.75%
Carrying Amount							$ 32,000,000		32,000,000
Estimated Fair Value							31,840,000		32,320,000
Senior Notes | Senior Unsecured Notes
Debt Instrument [Line Items]
Carrying Amount							950,000,000		950,000,000
Estimated Fair Value							$ 968,375,000		1,023,375,000
Senior Notes | Series A 4.68% notes due 2026
Debt Instrument [Line Items]
Contractual Interest Rate						4.68%	4.68%				4.68%
Effective Interest Rate as of March 31, 2020						4.77%	4.77%
Carrying Amount							$ 200,000,000		200,000,000
Estimated Fair Value							$ 210,000,000		217,750,000
Face amount of debt											$ 200,000,000.0
Senior Notes | Series B 4.86% notes due 2029
Debt Instrument [Line Items]
Contractual Interest Rate						4.86%	4.86%				4.86%
Effective Interest Rate as of March 31, 2020						4.92%	4.92%
Carrying Amount							$ 400,000,000		400,000,000
Estimated Fair Value							$ 414,500,000		439,000,000
Face amount of debt											$ 400,000,000.0
Senior Notes | Series C 4.10% notes due 2030
Debt Instrument [Line Items]
Contractual Interest Rate						4.10%	4.10%			4.10%
Effective Interest Rate as of March 31, 2020						4.15%	4.15%
Carrying Amount							$ 350,000,000		350,000,000
Estimated Fair Value							343,875,000		366,625,000
Face amount of debt										$ 350,000,000.0
Term Loans | Total 2020 Senior Unsecured Term Loan A Facility
Debt Instrument [Line Items]
Carrying Amount							602,075,000		0
Estimated Fair Value							$ 601,323,000		0
Term Loans | 2020 Senior Unsecured Term Loan Tranche A-1
Debt Instrument [Line Items]
Effective Interest Rate as of March 31, 2020						2.83%	2.83%
Carrying Amount							$ 425,000,000		0
Estimated Fair Value							$ 424,469,000		0
Face amount of debt								$ 425,000,000.0
Term Loans | 2020 Senior Unsecured Term Loan Tranche A-1 | LIBOR
Debt Instrument [Line Items]
Contractual Interest Rate						0.95%
Term Loans | 2020 Senior Unsecured Term Loan Tranche A-2
Debt Instrument [Line Items]
Effective Interest Rate as of March 31, 2020						2.76%	2.76%
Carrying Amount							$ 177,075,000		0
Estimated Fair Value							$ 176,854,000		0
Face amount of debt	$ 250,000,000.0					$ 250,000,000.0
Term Loans | 2020 Senior Unsecured Term Loan Tranche A-2 | CDOR
Debt Instrument [Line Items]
Contractual Interest Rate						0.095%
Term Loans | 2018 Senior Unsecured Term Loan A Facility
Debt Instrument [Line Items]
Effective Interest Rate as of March 31, 2020						3.14%	3.14%
Carrying Amount							$ 0		475,000,000
Estimated Fair Value							$ 0		472,625,000
Face amount of debt								$ 475,000,000
Term Loans | 2018 Senior Unsecured Term Loan A Facility | LIBOR
Debt Instrument [Line Items]
Contractual Interest Rate						0.95%
Revolving Credit Facility | Line of Credit | 2018 Senior Unsecured Term Loan A Facility | LIBOR
Debt Instrument [Line Items]
Contractual Interest Rate		1.00%	1.45%	1.45%	2.35%
Revolving Credit Facility | Line of Credit | 2020 Senior Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Effective Interest Rate as of March 31, 2020						0.20%	0.20%
Carrying Amount							$ 0
Estimated Fair Value							$ 0
Number of extensions | extension	2							2
Extension term	6 months
Revolving Credit Facility | Line of Credit | 2020 Senior Unsecured Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Contractual Interest Rate						0.85%
Revolving Credit Facility | Line of Credit | 2018 Senior Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Effective Interest Rate as of March 31, 2020						0.36%	0.36%
Carrying Amount									0
Estimated Fair Value									$ 0
Revolving Credit Facility | Line of Credit | 2018 Senior Unsecured Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Contractual Interest Rate						0.90%