Employee Benefit Plans - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 entrant	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Number of new entrants after pension plans were frozen	0
Employer contributions to the pension plans	$ 0.7	$ 0.6
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions for current year	3.3
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions for current year	$ 0.3