Fair Value Measurements - (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments, Owned, State and Municipal Government Obligations, at Fair Value	$ 95,819	$ 116,089
Financial Instruments, Owned, Corporate Equities, at Fair Value	842	835
Assets, Fair Value Disclosure	96,661	116,924
Foreign Currency Contracts, Liability, Fair Value Disclosure	385	85
Business Combination, Contingent Consideration, Liability	3,726	3,703
Liabilities, Fair Value Disclosure	$ 4,111	3,788
Fair Value Inputs Discount Rate 3	9.10%
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ 3,726	3,703
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	117
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	$ (94)
Fair Value, Level 3 Transfers out, Description	0
Convertible Debt	$ 59,885	57,846
Long-term Debt, Fair Value	$ 60,996	$ 60,630
Fair Value Inputs Discount Rate 2	5.00%	5.00%
Long-term Debt, Contingent Payment of Principal or Interest	0	0
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments, Owned, State and Municipal Government Obligations, at Fair Value	$ 0	$ 0
Financial Instruments, Owned, Corporate Equities, at Fair Value	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure		0
Assets, Fair Value Disclosure	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0
Business Combination, Contingent Consideration, Liability	0	0
Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments, Owned, State and Municipal Government Obligations, at Fair Value	95,819	116,089
Financial Instruments, Owned, Corporate Equities, at Fair Value	842	835
Assets, Fair Value Disclosure	96,661	116,924
Foreign Currency Contracts, Liability, Fair Value Disclosure	385	85
Business Combination, Contingent Consideration, Liability	0	0
Liabilities, Fair Value Disclosure	385	85
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments, Owned, State and Municipal Government Obligations, at Fair Value	0	0
Financial Instruments, Owned, Corporate Equities, at Fair Value	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure		0
Assets, Fair Value Disclosure	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0
Business Combination, Contingent Consideration, Liability	3,726	3,703
Liabilities, Fair Value Disclosure	$ 3,726	$ 3,703