Business Segment Information (Schedule of Revenues And Assets Based On Location) (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Revenues | $ 405,057 | $ 408,682 | $ 404,830 | $ 405,598 | $ 408,219 | $ 386,018 | $ 372,331 | $ 359,984 | $ 1,624,167 | $ 1,526,552 | $ 1,401,545 |
Assets | 1,971,668 | 1,853,369 | 1,971,668 | 1,853,369 | |||||||
United States | |||||||||||
Revenues | 1,348,130 | 1,298,381 | 1,191,640 | ||||||||
Assets | 1,612,202 | 1,471,260 | 1,612,202 | 1,471,260 | |||||||
International operations | |||||||||||
Revenues | 276,037 | 228,171 | $ 209,905 | ||||||||
Assets | $ 359,466 | $ 382,109 | $ 359,466 | $ 382,109 |