LONG-TERM INCENTIVE COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2018

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Total Expense Recorded for Stock Based Compensation

The following table presents the total stock-based compensation expense recorded for stock-based compensation arrangements for the periods indicated (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Service condition stock-based compensation expense	$	2,434	$	2,591	$	7,759	$	7,828
Performance condition stock-based compensation expense	1,107		1,454		3,471		3,949
Stock-based compensation expense under the Plan	3,541		4,045		11,230		11,777
Canadian Plan stock-based compensation expense	154		188		428		521
Total stock-based compensation expense	$	3,695	$	4,233	$	11,658	$	12,298

Restricted Stock Subject Only to a Service Condition

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Status and Changes in Restricted Stock Grants that Subject to Service Condition

The following table details the status and changes in our restricted stock grants subject only to a service condition for the nine months ended September 30, 2018:

	Shares		Weighted Average Grant Date Fair Value
Non-vested, January 1, 2018	519,375		$	55.44
Granted	172,366		55.92
Vested	(203,504	)	53.49
Forfeited	(29,229	)	56.55
Non-vested, September 30, 2018	459,008		$	56.42

Restricted Shares Subject to Service and Performance Conditions

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Status and Changes in Restricted Stock Grants that Subject to Service Condition

The following table details the status and changes in our restricted stock grants subject to service and performance conditions for the nine months ended September 30, 2018:

	Shares		Weighted Average Grant Date Fair Value
Non-vested, January 1, 2018	165,918		$	55.85
Granted	84,829		55.46
Vested	(98,281	)	55.81
Forfeited	—		—
Non-vested, September 30, 2018	152,466		$	55.66