Supplemental Cash Flows Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Supplemental disclosure of cash flow data:
Interest paid	$ 12,680	$ 10,230
Income taxes paid	4,340	4,965
Cash paid for amounts in operating lease liabilities	2,533	2,305
Supplemental disclosure of non-cash investing and financing activities:
Acquisition holdback payable		337
Exchanges of Class C and Class D common stock for Class A common stock	882	20,293
Operating lease liabilities arising from obtaining new or modified right-of-use assets	2,262	$ 8,098
Decrease in operating lease liabilities from lease modifications reducing the right-of-use-assets	$ (6,701)