Employee Benefit Plans (Other Investment Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Unrealized gains relating to instruments held at the reporting date			$ 635
Transfer out of Level 3	(14,500)	0	0
Nonqualified Supplemental Retirement Plans | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33,761	30,068
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	33,761	30,068
Nonqualified Supplemental Retirement Plans | Insurance contracts | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,805	12,999
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	14,805	12,999
Nonqualified Supplemental Retirement Plans | United States equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,579	4,741
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	5,579	4,741
Nonqualified Supplemental Retirement Plans | Global equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,338	2,109
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	2,338	2,109
Nonqualified Supplemental Retirement Plans | Fixed income | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,039	10,219
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	11,039	10,219
Nonqualified Supplemental Retirement Plans | Level 1 | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,917	6,850
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	7,917	6,850
Nonqualified Supplemental Retirement Plans | Level 1 | Insurance contracts | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 1 | United States equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,579	4,741
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	5,579	4,741
Nonqualified Supplemental Retirement Plans | Level 1 | Global equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,338	2,109
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	2,338	2,109
Nonqualified Supplemental Retirement Plans | Level 1 | Fixed income | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 2 | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25,844	17,618
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	25,844	17,618
Nonqualified Supplemental Retirement Plans | Level 2 | Insurance contracts | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,805	7,399
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	14,805	7,399
Nonqualified Supplemental Retirement Plans | Level 2 | United States equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 2 | Global equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 2 | Fixed income | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,039	10,219
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	11,039	10,219
Nonqualified Supplemental Retirement Plans | Level 3 | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	5,600
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	5,600
Nonqualified Supplemental Retirement Plans | Level 3 | Insurance contracts | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	5,600	5,332
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at beginning of period	5,600	5,332	5,069
Unrealized gains relating to instruments held at the reporting date	0	268	263
Transfer out of Level 3	(5,600)	0	0
Fair value of plan assets at end of period	0	5,600	5,332
Nonqualified Supplemental Retirement Plans | Level 3 | United States equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 3 | Global equities | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Nonqualified Supplemental Retirement Plans | Level 3 | Fixed income | Deferred Costs, Noncurrent
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	$ 0	$ 0