Employee Benefit Plans (Plan Assets at Fair Value) (Details) - Employee Pension Plans [Member] - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		$ 63,109	$ 71,541	$ 66,057
Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		46,608	40,793
Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets	[1]	16,501	30,748
Quoted prices in active markets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		44,023	40,793
Quoted prices in active markets (Level 1) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		44,023	40,793
Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		2,585
Significant other observable inputs (Level 2) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		2,585
Cash and Cash Equivalents [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		7,587	2,390
Cash and Cash Equivalents [Member] | Quoted prices in active markets (Level 1) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		7,587	2,390
Fixed Income Funds [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		2,585	18,031
Fixed Income Funds [Member] | Quoted prices in active markets (Level 1) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets			18,031
Fixed Income Funds [Member] | Significant other observable inputs (Level 2) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		2,585
Equity Funds [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		36,436	20,372
Equity Funds [Member] | Quoted prices in active markets (Level 1) [Member] | Non-Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		36,436	20,372
Equity Partnerships [Member] | Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		5,580	8,711
Hedge Funds Investments [Member] | Closely Held Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan's assets		$ 10,921	$ 22,037

[1] Closely held funds in private investment were comprised of a combination of Level 1, 2 and 3 investments, but were not categorized in the fair value hierarchy because they were measured at NAV using the practical expedient under ASC 820, Fair Value Measurement ("ASC 820").