Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Total revenues	$ 299,893	$ 280,623
Total long-lived assets	655,691		$ 593,595
UNITED STATES
Total revenues	231,343	209,076
Total long-lived assets	573,817		530,785
CANADA
Total revenues	17,053	19,622
IRELAND
Total revenues	15,623	17,101
All Other Countries [Member]
Total revenues	35,874	$ 34,824
Total long-lived assets	$ 81,874		$ 62,810