Capital Stock and Share-Based Compensation - Performance Stock Units Issued and Outstanding (Details) - 2010 Incentive Award Plan - Performance Stock Units $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares
Performance Stock Units
Unvested, Beginning Balance | shares	29	[1]
Granted | shares	60	[1]
Unvested, Ending Balance | shares	89	[1]
Expected to vest at end of period | shares	89	[1]
Weighted Average Grant Date Fair Value
Unvested, Beginning Balance | $ / shares	$ 14.13
Granted | $ / shares	28.80
Unvested, Ending Balance | $ / shares	24.00
Expected to vest at end of period | $ / shares	$ 24.00
Weighted Average Remaining Vesting Period (in years)
Unvested at end of period	1 year 8 months 4 days
Expected to vest at end of period	1 year 8 months 4 days
Aggregate Intrinsic Value
Unvested at end of period | $	$ 4,474	[2]
Expected to vest at end of period | $	$ 4,474	[2]

[1] The unvested PSUs are shown in this table at target, except for the number of shares vested, which reflect the shares earned. As of December 31, 2017, the maximum number of PSUs available to be earned is approximately 179 thousand.

[2] The aggregate intrinsic value is calculated based on the fair value of $50.00 per share of the Company’s common stock on December 31, 2017 due to the fact that the performance stock units carry a $0 purchase price