Fair Value of Financial Instruments (Tables)
 6 Months Ended
Jun. 30, 2016
FAIR VALUE OF FINANCIAL INSTRUMENTS [abstract]  
Fair value of financial instruments
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
June 30, 2016
 
 
December 31, 2015
 
  
Book Value
 
 
Fair Value
 
 
Book Value
 
 
Fair Value
Cash and cash equivalents
  
$
140,529
 
 
$
140,529
 
 
$
163,412
 
 
$
163,412
Restricted cash
  
$
2,671
 
 
$
2,671
 
 
$
13,480
 
 
$
13,480
Investments in available-for-sale-securities
  
$
5,303
 
 
$
5,303
 
 
$
5,173
 
 
$
5,173
Loan receivable from affiliate companies
  
$
21,827
 
 
$
21,827
 
 
$
16,474
 
 
$
16,474
Capital lease obligations, including current portion
  
$
(18,555
 ) 
 
$
(18,555
 ) 
 
$
(20,649
)
 
$
(20,649
Senior and ship mortgage notes, net
  
$
(1,352,860)
 
 
$
(692,238
 ) 
 
$
(1,350,941
)
 
$
(735,002
Long-term debt, including current portion
  
$
(276,036
 ) 
 
$
(279,476
 ) 
 
$
(230,367
)
 
$
(233,526
Long term payable to affiliate companies
  
$
(6,430
 ) 
 
$
(6,430
 ) 
 
$
—
 
 
$
—
Fair value measurements on a recurring basis
 
 
  
 
 
 
Fair Value Measurements as of June 30, 2016
Assets
  
Total
 
  
Quoted Prices in
Active Markets for
 Identical Assets
 (Level I)
 
  
Significant  Other
 Observable
 Inputs
 (Level II)
 
  
Significant
 Unobservable
 Inputs
 (Level III)
Investments in available-for-sale securities
  
$
5,303
  
  
$
5,303
  
  
$
—  
 
  
$ 
—  
Total
  
$
5,303
  
  
$
5,303
  
  
$
—  
 
  
$
—  
 
 
 
  
 
 
 
Fair Value Measurements as of December 31, 2015
Assets
  
Total
 
  
Quoted Prices in
Active Markets for
 Identical Assets
 (Level I)
 
  
Significant  Other
 Observable
 Inputs
 (Level II)
 
  
Significant
 Unobservable
 Inputs
 (Level III)
Investments in available-for-sale securities
  
$
5,173
  
  
$
5,173
  
  
$
—  
 
  
$ 
—  
Total
  
$
5,173
  
  
$
5,173
  
  
$
—  
 
  
$
—  
Fair value measurements on a nonrecurring basis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
Fair Value Measurements at June 30, 2016
 
 
  
Total
 
 
(Level I)
 
 
(Level II)
 
 
(Level III)
 
Cash and cash equivalents
  
$
140,529
 
 
$
140,529
 
 
$
—  
 
 
$
—  
 
Restricted cash
  
$
2,671
 
 
$
2,671
 
 
$
—  
 
 
$
—  
 
Loan receivable from affiliate companies(2)
 
$
21,827
 
 
$
—  
 
 
$
21,827
 
 
$
—  
 
Capital lease obligations, including current portion(1)
  
$
(18,555
)
 
$
—  
 
 
$
(18,555
)
 
$
—  
 
Senior and ship mortgage notes
  
$
(692,238
)
 
$
(692,238
)
 
$
—  
 
 
$
—  
 
Long-term debt, including current portion(1)
  
$
(279,476
)
 
$
—  
 
 
$
(279,476
)
 
$
—  
 
Long term payable to affiliate companies (2)
 
$
(6,430
 ) 
 
$
         —
 
 
$
(6,430
 ) 
 
$
     —
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
Fair Value Measurements at December 31, 2015
 
 
  
Total
 
 
(Level I)
 
 
(Level II)
 
 
(Level III)
 
Cash and cash equivalents
  
$
163,412
 
 
$
163,412
 
 
$
—  
 
 
$
—  
 
Restricted cash
  
$
13,480
 
 
$
13,480
 
 
$
—  
 
 
$
—  
 
Loan receivable from affiliate companies(2)
  
$
16,474
 
 
$
—  
 
 
$
16,474
 
 
$
—  
 
Capital lease obligations, including current portion(1)
  
$
(20,649
)
 
$
—  
 
 
$
(20,649
)
 
$
—  
 
Senior and ship mortgage notes
  
$
(735,002
)
 
$
(735,002
)
 
$
—  
 
 
$
—  
 
Long-term debt, including current portion(1)
  
$
(233,526
)
 
$
—  
 
 
$
(233,526
)
 
$
—  
 
 
(1
 )The fair value of the Company's long-term debt is estimated based on currently available debt with similar contract terms, interest rates and remaining maturities, published quoted market prices as well as taking into account the Company's creditworthiness.
(2
 )The fair value of the Company's loan receivable from affiliate companies and long-term payable to affiliate companies is estimated based on currently available debt with similar contract terms, interest rate and remaining maturities as well as taking into account the counterparty's creditworthiness.