Debt Revolving Credit Agreement (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			3 Months Ended	12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2014 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Jan. 21, 2014 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Dec. 31, 2011 Revolving Credit Facility [Member]	Dec. 31, 2013 Minimum Revolving Credit Facility [Member]	Dec. 31, 2013 Maximum Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest Income, Other	$ 35	$ 222	$ 254
Line of Credit Facility, Maximum Borrowing Capacity					100,000	125,000		100,000
Aggregate principal amount available for a Canadian subfacility					20,000
Aggregate principal amount available for letters of credit					20,000
Aggregate principal amount available for swingline loans					10,000
Maturity date					Dec. 15, 2015
Customary base rate plus an applicable margin percentage									0.50%	1.00%
Adjusted LIBOR rate plus an applicable margin									1.50%	2.00%
Weighted average interest rate for borrowings					2.71%		2.71%	1.63%
Line of Credit, Terms, Provision to Increase the Aggregate Amount of Commitments Under Certain Conditions, Amount				25,000	50,000
Credit Facility Incremental Commitment						25,000
Ratio of EBITDA to fixed charges					1.1
Percentage of maximum calculated borrowing base to fixed charge of EBITDA									10.00%	12.50%
Calculated borrowing base									10,000	12,500
Excess availability					$ 90,308