Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Restricted Stock Transactions

Transactions related to restricted stock awards are as follows:

	Shares		Weighted Average Grant Date Fair Value
	(share amounts in thousands)
Unvested balance, January 1, 2017	4,201		$	12.86
Granted	1,598		15.84
Vested	(1,304	)	13.09
Forfeited	(27	)	14.44
Unvested balance, December 31, 2017	4,468		$	13.85

Schedule of stock compensation expense recognized

Stock compensation expense recognized by the Company was as follows:

	For the Year Ended December 31,
	2015		2016		2017
	(in thousands)
Stock compensation expense:
Included in general and administrative	$	11,633	$	14,607	$	15,706
Included in cost of services	3,046		2,806		3,578
Total	$	14,679	$	17,413	$	19,284

Schedule of stock compensation expense based on current stock-based awards for each of the next five years

Stock compensation expense based on current stock-based awards for each of the next five years is estimated to be as follows:

	2018		2019		2020		2021		2022
	(in thousands)
Stock compensation expense	$	17,547	$	11,946	$	6,315	$	1,472	$	6