Debt (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit agreement term	4 years
Current borrowing capacity	$ 100,000,000
Maximum borrowing capacity	125,000,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	20,000,000
Swing Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 5,000,000