Stock-Based Compensation - Schedule of Stock Option Activity and Weighted Average Exercise Prices (Details) - Employee Stock Option $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Options
Outstanding at January 1, 2017 (in shares) | shares	1,090,160
Granted (in shares) | shares	267,039
Forfeited or expired (in shares) | shares	(72,015)
Exercised (in shares) | shares	(14,520)
Unearned performance-based options (in shares) | shares	(19,362)
Outstanding at September 30, 2017 (in shares) | shares	1,251,302
Options exercisable at September 30, 2017 (in shares) | shares	963,891
Weighted- Average Exercise Price
Outstanding at January 1, 2017 (in dollars per share) | $ / shares	$ 48.02
Granted (in dollars per share) | $ / shares	34.79
Forfeited or expired (in dollars per share) | $ / shares	44.39
Exercised (in dollars per share) | $ / shares	26.68
Unearned performance-based options (in dollars per share) | $ / shares	59.97
Outstanding at September 30, 2017 (in dollars per share) | $ / shares	45.47
Options exercisable at September 30, 2017 (in dollars per share) | $ / shares	$ 42.82
Weighted-Average Remaining Contractual Term (Years)
Weighted-average remaining contractual term, outstanding at September 30, 2017	4 years 2 months 12 days
Weighted-average remaining contractual term, options exercisable at September 30, 2017	3 years
Aggregate Intrinsic Value as of September 30, 2017
Aggregate intrinsic value outstanding at September 30, 2017 | $	$ 2,235
Aggregate intrinsic value of options exercisable at September 30, 2017 | $	$ 612