Stock-Based Compensation, Restricted Stock Activity (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding Shares, Beginning balance (in shares) | shares	1,993	[1]
Granted | shares	1,164	[1]
Vested | shares	(673)	[1]
Forfeited | shares	(38)	[1]
Outstanding Shares, Ending balance (in shares) | shares	2,446	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, Weighted Average Grant Date Fair Value, Beginning balance (in usd per share) | $ / shares	$ 21.92
Granted, Weighted Average Grant Date Fair Value | $ / shares	22.21
Vested, Weighted Average Grant Date Fair Value | $ / shares	20.49
Forfeited, Weighted Average Grant Date Fair Value | $ / shares	24.14
Outstanding Weighted Average Grant Date Fair Value, Ending balance (in usd per share) | $ / shares	$ 22.42

[1] (a) In thousands