Commitments, Contingencies And Legal Proceedings (Details) (USD $)	12 Months Ended							3 Months Ended	12 Months Ended			3 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2011 Operating and Administrative Expenses [Member]	Dec. 31, 2013 Operating and Administrative Expenses [Member]	Apr. 30, 2011 Unfavorable Regulatory Action [Member]	Dec. 31, 2009 Unfavorable Regulatory Action [Member]	Jun. 30, 2011 Unfavorable Regulatory Action [Member] Operating and Administrative Expenses [Member]	Dec. 31, 2010 DSPCon, Inc [Member]	Dec. 31, 2013 DSPCon, Inc [Member]	Dec. 31, 2011 DSPCon, Inc [Member]	Dec. 20, 2010 DSPCon, Inc [Member]	Dec. 20, 2010 Client Relationships [Member] DSPCon, Inc [Member]	Dec. 20, 2010 Developed Technology [Member] DSPCon, Inc [Member]	Dec. 20, 2010 Trademarks [Member] DSPCon, Inc [Member]	Dec. 31, 2013 Year-End Adjustment [Member]
Loss Contingencies [Line Items]
Operating leases rent expense	$ 12,100,000	$ 12,300,000	$ 13,000,000
Operating leases sub-lease proceeds	400,000	200,000	700,000
Stop loss insurance for workers compensation claims per incident	250,000
Stop loss insurance health care benefit claims per incident	200,000
Accrual for estimated claims exposure	2,100,000	2,000,000
Accrual for workers’ compensation estimated claims exposure	5,200,000	4,000,000
Estimated possible loss contingency										2,500,000	12,300,000
Benefit related to settlement								9,700,000	3,300,000			9,700,000
Business Combination, Consideration Transferred													6,900,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net																5,600,000	1,700,000	500,000	100,000
Goodwill	62,280,000						62,009,000								3,400,000
Contingent payment amount														400,000
Fair value of contingent consideration	$ 600,000			$ 500,000	$ 400,000	$ 300,000								$ 200,000						$ 1,800,000