Financial Instruments and Fair Value Measurements - Debt Instruments with Carrying Values Different than Estimated Fair Values (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	$ 2,914,186	$ 2,913,217
Revolving Credit Facilities and term loans	688,409	598,242
Mortgage Indebtedness	918,331	982,509
Total indebtedness	4,520,926	4,493,968
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	3,026,001	3,056,896
Revolving Credit Facilities and term loans	691,460	601,131
Mortgage Indebtedness	946,958	1,012,869
Total indebtedness	$ 4,664,419	$ 4,670,896