Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS. (Details)

v3.19.1
FAIR VALUE MEASUREMENTS. (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Assets:    
Assets $ 1,155 $ 15,022
Liabilities:    
Liabilities (5,156)  
Level 1 [Member]    
Assets:    
Assets 1,155 1,765
Liabilities:    
Liabilities (5,156)  
Level 2 [Member]    
Assets:    
Assets 13,257
Liabilities:    
Liabilities  
Level 3 [Member]    
Assets:    
Assets
Liabilities:    
Liabilities  
Derivative Financial Instrument [Member]    
Assets:    
Assets 1,155 [1] 1,765 [2]
Liabilities:    
Liabilities (5,156) [1] (6,309)
Derivative Financial Instrument [Member] | Level 1 [Member]    
Assets:    
Assets 1,155 [1] 1,765 [2]
Liabilities:    
Liabilities (5,156) [1] (6,309)
Derivative Financial Instrument [Member] | Level 2 [Member]    
Assets:    
Assets [1] [2]
Liabilities:    
Liabilities [1]
Derivative Financial Instrument [Member] | Level 3 [Member]    
Assets:    
Assets [1] [2]
Liabilities:    
Liabilities [1]
Defined Benefit Plan Assets Large U.S. Equity [Member]    
Assets:    
Assets [3]   $ 3,621
Liabilities:    
Benefit plan allocation percentage [1]   27.00%
Defined Benefit Plan Assets Large U.S. Equity [Member] | Level 1 [Member]    
Assets:    
Assets [3]  
Defined Benefit Plan Assets Large U.S. Equity [Member] | Level 2 [Member]    
Assets:    
Assets [3]   3,621
Defined Benefit Plan Assets Large U.S. Equity [Member] | Level 3 [Member]    
Assets:    
Assets [3]  
Defined Benefit Plan Assets Small/Mid U.S. Equity [Member]    
Assets:    
Assets [4]   $ 1,844
Liabilities:    
Benefit plan allocation percentage [3]   14.00%
Defined Benefit Plan Assets Small/Mid U.S. Equity [Member] | Level 1 [Member]    
Assets:    
Assets [4]  
Defined Benefit Plan Assets Small/Mid U.S. Equity [Member] | Level 2 [Member]    
Assets:    
Assets [4]   1,844
Defined Benefit Plan Assets Small/Mid U.S. Equity [Member] | Level 3 [Member]    
Assets:    
Assets [4]  
Defined Benefit Plan Assets International Equity [Member]    
Assets:    
Assets [5]   $ 2,106
Liabilities:    
Benefit plan allocation percentage [4]   16.00%
Defined Benefit Plan Assets International Equity [Member] | Level 1 [Member]    
Assets:    
Assets [5]  
Defined Benefit Plan Assets International Equity [Member] | Level 2 [Member]    
Assets:    
Assets [5]   2,106
Defined Benefit Plan Assets International Equity [Member] | Level 3 [Member]    
Assets:    
Assets [5]  
Defined Benefit Plan Assets Fixed Income [Member]    
Assets:    
Assets [6]   $ 5,686
Liabilities:    
Benefit plan allocation percentage [5]   43.00%
Defined Benefit Plan Assets Fixed Income [Member] | Level 1 [Member]    
Assets:    
Assets [6]  
Defined Benefit Plan Assets Fixed Income [Member] | Level 2 [Member]    
Assets:    
Assets [6]   5,686
Defined Benefit Plan Assets Fixed Income [Member] | Level 3 [Member]    
Assets:    
Assets [6]  
[1] This category includes investments in funds comprised of equity securities of large U.S. companies. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund.
[2] Included in derivative instruments in the consolidated balance sheets.
[3] This category includes investments in funds comprised of equity securities of small- and medium-sized U.S. companies. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund.
[4] This category includes investments in funds comprised of equity securities of foreign companies including emerging markets. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund.
[5] This category includes investments in funds comprised of U.S. and foreign investment-grade fixed income securities, high-yield fixed income securities that are rated below investment-grade, U.S. treasury securities, mortgage-backed securities, and other asset-backed securities. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund.
[6] Amounts derived from the audited financial statements for the year ended December 31, 2018.