Revenue Recognition (Details)	9 Months Ended
	Sep. 30, 2013
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Typical service agreements	12 months
Fees and related labor costs, recognition period (current estimate of term of customer relationship)	48 months
Minimum [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Typical service agreements termination notice period	30 days
Maximum [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Typical service agreements termination notice period	90 days