Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Fair Value Measurements [Abstract]

Fair Value, Measurement Inputs, Disclosure [Text Block]

The following tables provide the assets and liabilities carried at fair value measured on a recurring basis at December 31, 2016 and December 31, 2015:

	Fair Value Measurements Using
	Carrying Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
December 31, 2016
Assets:
Available-for-sale debt securities:
Municipal notes and bonds	$	87,029	$	—	$	87,029	$	—
Corporate bonds	843		—		843		—
Foreign currency forward contracts	312		—		312		—
Total Assets	$	88,184	$	—	$	88,184	$	—
Liabilities:
Contingent consideration - acquisitions	3,251		—		—		3,251
Total Liabilities	$	3,251	$	—	$	—	$	3,251
December 31, 2015
Assets:
Available-for-sale debt securities:
Municipal notes and bonds	$	116,089	$	—	$	116,089	$	—
Corporate bonds	835		—		835		—
Total Assets	$	116,924	$	—	$	116,924	$	—
Liabilities:
Foreign currency forward contracts	$	85	$	—	$	85	$	—
Contingent consideration - acquisitions	3,703		—		—		3,703
Total Liabilities	$	3,788	$	—	$	85	$	3,703

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

This table presents a reconciliation for all liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the year ended December 31, 2016:

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
Liabilities:
Balance at December 31, 2015	$	3,703
Additions	—
Total loss due to remeasurement included in selling, general and administrative expense	170
Payments	(622		)
Transfer into (out of) Level 3	—
Balance at December 31, 2016	$	3,251

Fair value convertible senior notes [Table Text Block]

The following table reflects information pertaining to the Company’s convertible senior notes:

	December 31,
	2015
Net carrying value of convertible senior notes	$	57,846
Estimated fair value of convertible senior notes	$	60,630
Estimated interest rate used in discounted cash flow model	5.0		%
Fair value of contingent interest	$	—