Financial Instruments and Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 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):

	September 30, 2018				December 31, 2017
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Senior Notes	$	1,896,458	$	1,890,538	$	2,810,100	$	2,884,272
Revolving Credit Facilities and term loans		303,540		306,206		398,130		400,119
Mortgage Indebtedness		185,004		185,128		641,082		653,185
	$	2,385,002	$	2,381,872	$	3,849,312	$	3,937,576