Employee Benefit Plans (Summary of Changes in the Fair Value of the Level 3 Plan Assets) (Details) - Employee Pension Plans [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Change in Fair Value of Plan Assets
Balance at beginning of year		$ 75,956	$ 72,617
Balance at end of year		72,296	75,956
Level 3 [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		25,131	23,724
Realized gains (losses)		(82)	16
Unrealized gains (losses)		(70)	1,464
Purchases		8,498	1,076
Sales		(5,926)	(3,839)
Reclassified to Level 3	[1]		2,690
Balance at end of year		27,551	25,131
Hedge Fund Investments: Long-Short Equity Fund [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		28,633
Balance at end of year		29,010	28,633
Hedge Fund Investments: Long-Short Equity Fund [Member] | Level 3 [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		12,755	10,863
Realized gains (losses)		(50)
Unrealized gains (losses)		581	843
Purchases		5,631	1,049
Sales		(2,547)
Balance at end of year		16,370	12,755
Hedge Fund Investments: Event Driven Fund [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		13,033
Balance at end of year		10,602	13,033
Hedge Fund Investments: Event Driven Fund [Member] | Level 3 [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		9,562	8,863
Realized gains (losses)		(16)
Unrealized gains (losses)		(585)	505
Purchases			16
Sales		(1,977)	(2,512)
Reclassified to Level 3	[1]		2,690
Balance at end of year		6,984	9,562
Hedge Fund Investment: Distressed Credit [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		1,320
Balance at end of year		935	1,320
Hedge Fund Investment: Distressed Credit [Member] | Level 3 [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		1,320	2,199
Realized gains (losses)		(7)	13
Unrealized gains (losses)		(28)	57
Purchases			5
Sales		(350)	(954)
Balance at end of year		935	1,320
Hedge Fund Investments: Multi-Strategy Fund [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		1,494
Balance at end of year		1,262	1,494
Hedge Fund Investments: Multi-Strategy Fund [Member] | Level 3 [Member]
Change in Fair Value of Plan Assets
Balance at beginning of year		1,494	1,799
Realized gains (losses)		(9)	3
Unrealized gains (losses)		(38)	59
Purchases		225	6
Sales		(410)	(373)
Balance at end of year		1,262	$ 1,494
Hedge Fund Investments: Private Credit [Member]
Change in Fair Value of Plan Assets
Balance at end of year		2,000
Hedge Fund Investments: Private Credit [Member] | Level 3 [Member]
Change in Fair Value of Plan Assets
Purchases		2,642
Sales		(642)
Balance at end of year		$ 2,000

[1] The transfer of $2.7 million from Level 2 to Level 3 was comprised of certain hedge funds that were moved due to liquidity.