Fair Value Measurement (Tables)

6 Months Ended

Jun. 30, 2017

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following tables summarize significant assets and liabilities measured at fair value in the condensed consolidated balance sheets on a recurring basis for each of the fair value levels (in thousands):



	Fair Value Measurement at Reporting Date Using
June 30, 2017	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	38,006	$	—	$	—	$	38,006
Total assets	$	38,006	$	—	$	—	$	38,006



December 31, 2016
Cash equivalents
Money market funds	$	10,057	$	—	$	—	$	10,057
Total assets	$	10,057	$	—	$	—	$	10,057



June 30, 2016
Cash equivalents
Money market funds	$	30,082	$	—	$	—	$	30,082
Commercial paper	4,994		—		—		4,994
Total assets	$	35,076	$	—	$	—	$	35,076

Schedule of Cash and Cash Equivalents [Table Text Block]

A reconciliation of cash equivalents to consolidated cash and cash equivalents is as follows



(in thousands)	June 30, 2017		December 31, 2016		June 30, 2016
Cash equivalents	$	38,006	$	10,057	$	35,076
Cash	140,062		179,269		126,142
Total cash and cash equivalents	$	178,068	$	189,326	$	161,218

Fair Value Measurements, Nonrecurring [Table Text Block]

The carrying values and estimated fair values of our financial instruments that are not required to be recorded at fair value in the condensed consolidated balance sheets were as follows:



		June 30, 2017				December 31, 2016				June 30, 2016
(in thousands)	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities	Level 1	$	107,811	$	107,381	$	127,779	$	127,365	$	77,612	$	77,678
Liabilities (including current maturities):
2019 Notes¹	Level 3	$	120,000	$	123,371	$	120,000	$	124,654	$	160,000	$	167,210
Credit Agreement term loan¹	Level 3	92,500		92,046		95,000		93,991		97,500		97,409
Credit Agreement - revolving credit facility¹	Level 3	30,000		29,672		30,000		29,452		—		—