Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on A Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent receivable	$ 12,200	$ 11,300
Total assets	51,616	46,757
Contingent consideration liabilities	17,000	15,800
Total liabilities	17,960	17,708
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent receivable	0	0
Total assets	39,416	35,457
Contingent consideration liabilities	0	0
Total liabilities	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent receivable	0	0
Total assets	0	0
Contingent consideration liabilities	0	0
Total liabilities	960	1,908
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent receivable	12,200	11,300
Total assets	12,200	11,300
Contingent consideration liabilities	17,000	15,800
Total liabilities	17,000	15,800
Interest Rate Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	960	1,908
Interest Rate Swaps | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Interest Rate Swaps | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	960	1,908
Interest Rate Swaps | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Money market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	39,416	35,457
Money market | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	39,416	35,457
Money market | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	0	0
Money market | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	$ 0	$ 0