Employee Benefit Plans - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 entrant	Mar. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Number of new entrants after pension plans were frozen	0
Employer contributions to the pension plans	$ 0	$ 700,000
Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net period benefit costs (less than $0.1 million for other post-retirement benefits)	100,000	100,000
Expected employer contributions for current year	200,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net period benefit costs (less than $0.1 million for other post-retirement benefits)	0	(100,000)
Expected employer contributions for current year	$ 0