Annual report pursuant to Section 13 and 15(d)

Long-Term Debt (Schedule Of Company's Borrowings) (Details)

v3.8.0.1
Long-Term Debt (Schedule Of Company's Borrowings) (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Long-term Debt, Gross $ 606,092 $ 835,773
Portion due within one year, net of related debt discount and issuance costs 77,842 163,202
Debt discount included in long-term debt (23,152) (34,970)
Debt issuance costs included in long-term debt (3,593) (6,517)
Long-term Debt, Excluding Current Maturities 501,505 631,084
Three Point Zero Percentage Convertible Notes [Member]    
Debt Instrument [Line Items]    
Convertible Debt 230,000 230,000
Debt discount included in long-term debt (22,900) (29,800)
Debt issuance costs included in long-term debt (2,300) (3,000)
Two Point Five Percentage Convertible Notes [Member]    
Debt Instrument [Line Items]    
Convertible Debt 64,455 157,128
Debt discount included in long-term debt   (4,800)
Debt issuance costs included in long-term debt   (800)
7.375% Senior Notes [Member]    
Debt Instrument [Line Items]    
Senior Notes, Noncurrent 153,090 160,699
Debt discount included in long-term debt (200) (400)
Debt issuance costs included in long-term debt (300) (500)
SEA-Vista Credit Facility [Member]    
Debt Instrument [Line Items]    
Debt issuance costs included in long-term debt (700) (2,000)
ISH Credit Facility [Member]    
Debt Instrument [Line Items]    
Debt issuance costs included in long-term debt (100)  
Other Debt Obligations [Member]    
Debt Instrument [Line Items]    
Other Long-term Debt 10,633 8,701
Debt issuance costs included in long-term debt (100) (100)
Sea-Vista [Member] | SEA-Vista Credit Facility [Member]    
Debt Instrument [Line Items]    
Secured Debt 135,714 279,245
ISH [Member] | ISH Credit Facility [Member]    
Debt Instrument [Line Items]    
Secured Debt $ 12,200 $ 0