Fair value measurements (Tables)

9 Months Ended

Sep. 30, 2015

Schedule of fair value of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy

The following tables set forth the assets and liabilities that we measure at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2015, and December 31, 2014 (in thousands):



			September 30, 2015
Description	Total		Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
“Available-for-sale” marketable equity securities	$	135,267	$	135,267	$	—	$	—
Liabilities:
Interest rate swap agreements	$	8,679	$	—	$	8,679	$	—



			December 31, 2014
Description	Total		Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
“Available-for-sale” marketable equity securities	$	74,265	$	74,265	$	—	$	—
Liabilities:
Interest rate swap agreements	$	909	$	—	$	909	$	—

Schedule of the book and fair values of our marketable securities, interest rate swap agreements, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loan

As of September 30, 2015, and December 31, 2014, the book and estimated fair values of our “available-for-sale” marketable equity securities, interest rate swap agreements, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were as follows (in thousands):



	September 30, 2015				December 31, 2014
	Book Value		Fair Value		Book Value		Fair Value
Assets:
“Available-for-sale” marketable equity securities	$	135,267	$	135,267	$	74,265	$	74,265

Liabilities:
Interest rate swap agreements	$	8,679	$	8,679	$	909	$	909
Secured notes payable	$	773,619	$	807,566	$	652,209	$	693,338
Unsecured senior notes payable	$	1,747,613	$	1,776,375	$	1,747,370	$	1,793,255
Unsecured senior line of credit	$	843,000	$	843,909	$	304,000	$	304,369
Unsecured senior bank term loans	$	950,000	$	951,540	$	975,000	$	976,010