Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2015

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 consolidated balance sheets on a recurring basis for each of the fair value levels (in thousands):



	Fair Value Measurement at Reporting Date Using
December 31, 2015	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	62,024	$	—	$	—	$	62,024
Total assets	$	62,024	$	—	$	—	$	62,024



	Fair Value Measurement at Reporting Date Using
December 31, 2014	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	60,618	$	—	$	—	$	60,618
Total assets	$	60,618	$	—	$	—	$	60,618

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):



December 31,	2015		2014
Cash equivalents	$	62,024	$	60,618
Cash	190,812		195,343
Total cash and cash equivalents	$	252,836	$	255,961

Fair Value, by Balance Sheet Grouping [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 consolidated balance sheets are as follows (in thousands):



December 31,		2015				2014
	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities	Level 1	$	105,695	$	105,336	$	102,067	$	101,808
Liabilities (including current maturities):
Senior notes payable¹	Level 3	$	160,000	$	165,731	$	200,000	$	220,226
Credit Agreement loan¹	Level 3	100,000		99,375		70,000		70,153

¹The fair values of the senior notes payable and Credit Agreement (defined in Note 12) loan are based on borrowing rates available to us for long-term loans with similar terms, average maturities, and credit risk.