Financial Instruments and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Debt Instruments with Carrying Values Different than Estimated Fair Values

Debt instruments with carrying values that are different than estimated fair values are summarized as follows (in thousands):

	March 31, 2018				December 31, 2017
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Senior Notes	$	1,917,833	$	1,937,522	$	2,810,100	$	2,884,272
Revolving Credit Facilities and term loans		318,452		320,218		398,130		400,119
Mortgage Indebtedness		1,505,235		1,538,103		641,082		653,185
	$	3,741,520	$	3,795,843	$	3,849,312	$	3,937,576