Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table summarizes our assets and liabilities at June 30, 2018 and December 31, 2017, respectively, that are measured at fair value on a recurring basis subsequent to initial recognition and indicates the fair value hierarchy of the valuation techniques utilized by us to determine such fair value (in thousands):

	Level	June 30, 2018			December 31, 2017
Deferred compensation plan assets	1	$	89,987		$	85,589
Corporate and municipal bonds	1	$	53,674		$	51,101
Deferred compensation plan liabilities	1	$	(89,987	)	$	(85,589	)
Interest rate swaps	2	$	1,950		$	1,131
Contingent purchase price liabilities	3	$	(46,528	)	$	(37,574	)

Change in Level 3 Fair Values of Contingent Purchase Price Liabilities

During the six months ended June 30, 2018 and 2017, there were no transfers between the valuation hierarchy Levels 1, 2 and 3. The following table summarizes the change in Level 3 fair values of our contingent purchase price liabilities for the six months ended June 30, 2018 and 2017 (pre-tax basis) (in thousands):

	2018			2017
Beginning balance – January 1	$	(37,574	)	$	(33,709	)
Additions from business acquisitions		(12,361	)		(17,526	)
Settlement of contingent purchase price liabilities		6,457			7,253
Change in fair value of contingencies		(2,562	)		1,032
Change in net present value of contingencies		(488	)		(276	)
Ending balance – June 30	$	(46,528	)	$	(43,226	)