Stock Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2017

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

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes RSU information for the three years ended December 31, 2017:

	2017		2016		2015
RSUs granted and unvested at beginning of period:	4,862,098		4,158,325		5,330,445
Granted	855,984		1,000,559		997,522
Vested	(1,993,507	)	(77,250	)	(1,938,000	)
Canceled	(246,594	)	(219,536	)	(231,642	)
RSUs granted and unvested at end of period:	3,477,981		4,862,098		4,158,325

Schedule of Share-based Compensation, Unearned Compensation Related to RSU's

The fair value of RSUs at the date of grant are recorded as unearned compensation, a component of stockholders’ equity, and expensed over the vesting period. Following is a summary of changes in unearned compensation for the three years ended December 31, 2017:

(In thousands)	2017			2016			2015
Unearned compensation at beginning of year	$	115,965		$	103,538		$	88,015
RSUs granted, net of cancellations	52,897			52,697			50,442
RSUs expensed	(38,796		)	(35,585		)	(30,691		)
RSUs forfeitures	(7,156		)	(4,685		)	(4,228		)
Unearned compensation at end of year	$	122,910		$	115,965		$	103,538