Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]

Fair value assets and liabilities measured on recurring basis

The following table provides a summary of the Company’s significant financial assets and liabilities carried at fair value and measured on a recurring basis (in thousands):

			Fair Value Measurements at December 31, 2016
	Carrying Value at December 31, 2016		Quoted Prices in Active Markets (Level 1)		Significant Other Observable  Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Restricted investments:
Rabbi Trust	$	15,662	$	—	$	15,662	$	—
Fixed income securities	1,782		—		1,782		—
Interest rate cap derivatives	15		—		15		—
Liabilities:
Interest rate swap derivatives	$	18,679	$	—	$	18,679	$	—

			Fair Value Measurements at December 31, 2015
	Carrying Value at December 31, 2015		Quoted Prices in Active Markets (Level 1)		Significant Other Observable  Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Restricted investments:
Rabbi Trust	$	13,071	$	—	$	13,071	$	—
Fixed income securities	1,717		—		1,717		—
Interest rate cap derivatives	93		—		93		—
Liabilities:
Interest rate swap derivatives	$	20,835	$	—	$	20,835	$	—