Pensions and Other Employee Benefits Plans (Fair Values of Pension Plan Assets) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		$ 31,466	$ 29,296
Pension plans' actual assets allocation		100.00%	100.00%
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		$ 28,531	$ 26,507
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		2,935	2,789	$ 2,788
Level 3 [Member] | Equity Long/Short Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		835	847	801
Level 3 [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		129	174	249
Level 3 [Member] | Distressed Opportunity Ltd. Partnership [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		448	313	368
Level 3 [Member] | Multi-Strategy Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		$ 1,523	1,455	$ 1,370
Liquid Return Seeking [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plans' actual assets allocation		61.00%
Liquid Return Seeking [Member] | Multi Asset Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[1]	$ 19,142
Pension plans' actual assets allocation	[1]	61.00%
Liquid Return Seeking [Member] | Level 2 [Member] | Multi Asset Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[1]	$ 19,142
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			$ 16,820
Pension plans' actual assets allocation			57.00%
Equity Securities [Member] | U.S. Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[2]		$ 7,159
Pension plans' actual assets allocation	[2]		24.00%
Equity Securities [Member] | U.S. Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[3]		$ 1,989
Pension plans' actual assets allocation	[3]		7.00%
Equity Securities [Member] | Global [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[4]		$ 2,333
Pension plans' actual assets allocation	[4]		8.00%
Equity Securities [Member] | Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[5]		$ 3,704
Pension plans' actual assets allocation	[5]		13.00%
Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			$ 15,799
Equity Securities [Member] | Level 2 [Member] | U.S. Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[2]		7,159
Equity Securities [Member] | Level 2 [Member] | U.S. Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[3]		1,989
Equity Securities [Member] | Level 2 [Member] | Global [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[4]		2,333
Equity Securities [Member] | Level 2 [Member] | Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[5]		3,704
Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			1,021
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			$ 12,476
Pension plans' actual assets allocation		30.00%	43.00%
Fixed Income Securities [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[6]	$ 9,389	$ 10,708
Pension plans' actual assets allocation	[6]	30.00%	37.00%
Fixed Income Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			$ 10,708
Fixed Income Securities [Member] | Level 2 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[6]	$ 9,389	10,708
Fixed Income Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets			1,768
Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		$ 2,935
Pension plans' actual assets allocation		9.00%
Alternative Investments [Member] | Equity Long/Short Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[7]	$ 835	$ 847
Pension plans' actual assets allocation	[7]	3.00%	3.00%
Alternative Investments [Member] | Real Estate Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[8]		$ 614
Pension plans' actual assets allocation	[8]		2.00%
Alternative Investments [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[9]	$ 129	$ 174
Pension plans' actual assets allocation	[9]	0.00%	0.00%
Alternative Investments [Member] | Distressed Opportunity Ltd. Partnership [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[10]	$ 448	$ 313
Pension plans' actual assets allocation	[10]	1.00%	1.00%
Alternative Investments [Member] | Multi-Strategy Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[11]	$ 1,523	$ 1,455
Pension plans' actual assets allocation	[11]	5.00%	5.00%
Alternative Investments [Member] | Level 2 [Member] | Real Estate Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[8]		$ 614
Alternative Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets		$ 2,935
Alternative Investments [Member] | Level 3 [Member] | Equity Long/Short Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[7]	835	847
Alternative Investments [Member] | Level 3 [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[9]	129	174
Alternative Investments [Member] | Level 3 [Member] | Distressed Opportunity Ltd. Partnership [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[10]	448	313
Alternative Investments [Member] | Level 3 [Member] | Multi-Strategy Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	[11]	$ 1,523	$ 1,455

[1] A single fund that invests in global equities, marketable real assets and fixed income securities. The fund has no limitation on redemptions.

[2] Investments in common stocks that rank among the largest 1,000 companies in the U.S. stock market.

[3] Investments in common stocks that rank among the small capitalization stocks in the U.S. stock market.

[4] Investments in common stocks across the world without being limited by national borders or to specific regions.

[5] Investments in common stocks of companies from developed and emerging countries outside the United States.

[6] Investments in bonds representing many sectors of the broad bond market with both short-term and intermediate-term maturities. The fund has no limitation on redemptions.

[7] Investments primarily in long and short positions in equity securities of U.S. and non-U.S. companies. The fund has semi-annual tender offer redemption periods on June 30 and December 31 and is reported on a one month lag.

[8] Investments in real estate through a fund of funds which invests in global public real estate securities (REITs).

[9] Fund invests in portfolios of secondary interest in established venture capital, buyout, mezzanine and special situation funds on a global basis. Fund is valued on a quarterly lag with adjustment for subsequent cash activity. The fund terminates on June 26, 2019, subject to extension for up to three one-year periods. Earlier redemptions are not permitted.

[10] Investments mainly in discounted debt securities, bank loans, trade claims and other debt and equity securities of financially troubled companies. This partnership has semi-annual withdrawal rights on June 30 and December 31. This fund is reported on a one month lag.

[11] Investments mainly in partnerships that have multi-strategy investment programs and do not rely on a single investment model. As of December 31, 2016 and 2015, investments include a partnership that has monthly liquidation rights with notice of 33 days.