8.SUPPLEMENTAL CONSOLIDATED BALANCE SHEET INFORMATION

Accounts Receivable, Net

The components of accounts receivable were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Billed amounts	$	170,049	$	183,656
Engagements in process		117,423		100,779
Allowance for uncollectible billed amounts		(13,589)		(14,967)
Allowance for uncollectible engagements in process		(9,009)		(7,713)
Accounts receivable, net	$	264,874	$	261,755

Receivables attributable to engagements in process represent balances for services that have been performed and earned but have not been billed to the client. Services are generally billed on a monthly basis for the prior month’s services. Our allowance for uncollectible accounts is based on historical experience and management judgment and may change based on market conditions or specific client circumstances.

Prepaid Expenses and Other Current Assets

The components of prepaid expenses and other current assets were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Notes receivable - current	$	2,227	$	2,636
Prepaid recruiting and retention incentives - current		9,444		9,173
Other prepaid expenses and other current assets		18,975		17,953
Prepaid expenses and other current assets	$	30,646	$	29,762

Other Assets

The components of other assets were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Notes receivable - non-current	$	3,083	$	2,943
Capitalized client-facing software		1,523		1,733
Prepaid recruiting and retention incentives - non-current		10,605		11,116
Prepaid expenses and other non-current assets		4,432		2,490
Other assets	$	19,643	$	18,282

Notes receivable, current and non-current, represent unsecured employee loans. These loans were issued to recruit or retain certain senior-level client-service employees. During the three months ended March 31, 2017, we issued an unsecured employee loan aggregating to $1.0 million, and during the three months ended March 31, 2016, no such loans were issued. The principal amount and accrued interest on these loans is either paid by the employee or forgiven by us over the term of the loans so long as the employee remains continuously employed by us and complies with certain contractual requirements. The expense associated with the forgiveness of the principal amount of the loans is amortized as compensation expense over the service period, which is consistent with the term of the loans.

Capitalized client-facing software is used by our clients as part of client engagements. These amounts are amortized into cost of services before reimbursable expenses over their estimated remaining useful life.

Prepaid recruiting and retention incentives, current and non-current, include sign-on and retention bonuses that are generally recoverable from an employee if the employee voluntarily terminates employment or if the employee’s employment is terminated for “cause” prior to fulfilling his or her obligations to us. These amounts are amortized as compensation expense over the period in which they are recoverable from the employee, generally in periods up to six years. During the three months ended March 31, 2017 and 2016, we granted $2.7 million and $6.5 million, respectively, in sign-on and retention bonuses.

Property and Equipment, Net

The components of property and equipment, net were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Furniture, fixtures and equipment	$	71,842	$	69,210
Software		85,066		83,766
Leasehold improvements		63,525		57,128
Property and equipment, at cost		220,433		210,104
Less: accumulated depreciation and amortization		(134,498)		(127,151)
Property and equipment, net	$	85,935	$	82,953

During the three months ended March 31, 2017, we invested $13.8 million in property and equipment ($3.4 million of which was accrued in prior periods), including $6.4 million in leasehold improvements related primarily to the build-out of our new Chicago corporate headquarters, $2.5 million in technology infrastructure and software, and $1.5 million in furniture.

Other Current Liabilities

The components of other current liabilities were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Deferred acquisition liabilities - current	$	12,180	$	10,780
Deferred revenue		18,964		21,258
Deferred rent - current		2,933		2,894
Other current liabilities		3,602		3,684
Total other current liabilities	$	37,679	$	38,616

Other Non-Current Liabilities

The components of other non-current liabilities were as follows (in thousands):


	March 31,		December 31,
	2017		2016
Deferred acquisition liabilities - non-current	$	791	$	943
Deferred rent - non-current		23,598		19,776
Other non-current liabilities		12,182		11,860
Total other non-current liabilities	$	36,571	$	32,579

Deferred acquisition liabilities, current and non-current, at March 31, 2017 consisted of cash obligations related to contingent and definitive purchase price considerations recorded at fair value and net present value, respectively. On April 3, 2017, $10.0 million was paid to the selling members of McKinnis Consulting Services LLC (McKinnis), which we acquired in December 2015, to settle a deferred acquisition liability. During the three months ended March 31, 2017, we recorded a fair value adjustment which increased deferred contingent acquisition liabilities by $1.2 million. See Note 12 – Fair Value for additional information regarding deferred contingent consideration fair value adjustments.

The current and non-current portions of deferred rent relates to tenant allowances and incentives on lease arrangements for our office facilities that expire at various dates through 2028.

At March 31, 2017, other non-current liabilities included $3.0 million of performance-based long-term incentive compensation liabilities. As part of our long-term incentive program for select senior-level client service employees and leaders, we grant restricted stock units which vest three years from the grant date. The value of equity granted is based on the achievement of certain performance targets during the year prior to grant.

Deferred revenue represents advance billings to our clients for services that have not yet been performed and earned.