Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Interest paid	$ 16,474	$ 11,573	$ 7,307
Taxes paid	5,699	316	3,125
Non-cash activities:
Purchases of property and equipment not paid	$ 1,380	$ 824	$ 2,104