Employee Benefit Plans - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014 entrant	Jun. 30, 2013	Jun. 30, 2014 entrant	Jun. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Number of new entrants after pension plans were frozen	0		0
Employer contributions to the pension plans	$ 0.9	$ 0.8	$ 1.6	$ 1.3
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions for current year			0.3
Minimum [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions for current year			2.2
Maximum [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions for current year			$ 3.3