Stock-Based Compensation - Schedule of Stock Option Activity and Weighted Average Exercise Prices (Details) - Employee Stock Option $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 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	(25,988)
Exercised (in shares) | shares	(11,401)
Unearned performance-based options (in shares) | shares	(19,362)
Outstanding at June 30, 2017 (in shares) | shares	1,300,448
Options exercisable at June 30, 2017 (in shares) | shares	966,617
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	59.97
Exercised (in dollars per share) | $ / shares	24.93
Unearned performance-based options (in dollars per share) | $ / shares	47.33
Outstanding at June 30, 2017 (in dollars per share) | $ / shares	45.34
Options exercisable at June 30, 2017 (in dollars per share) | $ / shares	$ 42.78
Weighted-Average Remaining Contractual Term (Years)
Weighted-average remaining contractual term, outstanding at June 30, 2017 (in years)	4 years 6 months
Weighted-average remaining contractual term, options exercisable at June 30, 2017 (in years)	3 years 3 months
Aggregate Intrinsic Value as of March 31, 2017
Aggregate intrinsic value outstanding at June 30, 2017 | $	$ 2,119
Aggregate intrinsic value of options exercisable at June 30, 2017 | $	$ 538