Stock Incentive Plans - Summary of Restricted Stock Activity (Details) - Restricted Stock $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares shares
Number of Restricted Stock
Outstanding, at beginning of period (in shares) | shares	1,355
Granted (in shares) | shares	135
Forfeited (in shares) | shares	(90)
Vested (in shares) | shares	(79)
Outstanding, at end of period (in shares) | shares	1,321
Weighted Average Grant Date Fair Value
Outstanding, as of beginning of period (in dollars per share) | $ / shares	$ 22.67
Granted (in dollars per share) | $ / shares	27.37
Forfeited (in dollars per share) | $ / shares	22.81
Vested (in dollars per share) | $ / shares	23.26
Outstanding, as of end of period (in dollars per share) | $ / shares	$ 23.23
Total Intrinsic Value of Restricted Stock Vested
Vested | $	$ 2,654