Other Long-Term Assets Components of Other Long-Term Assets(Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Convertible 2022 note hedge asset	$ 41,619,000	$ 25,471,000
Convertible 2021 note hedge asset	41,660,000	0
Cash surrender value of life insurance policies	1,895,000	1,824,000
Deferred financing fees	860,000	793,000
Installment receivables	385,000	466,000
Deferred taxes	470,000	837,000
Investments	103,000	108,000
Other	107,000	188,000
Other Assets	$ 87,099,000	$ 29,687,000