Stock-Based Compensation - Equity Awards Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Stock options
Number of Stock Options
Options, outstanding at beginning of period (in shares)	702,318
Options, granted (in shares)	0	0
Options, exercised (in shares)	(125,125)
Options, forfeited (in shares)	(1,438)
Options, outstanding at end of period (in shares)	575,755	702,318
Options, exercisable (in shares)	575,755
Weighted-Average Exercise Price
Options, weighted average exercise price, beginning of period (in usd per share)	$ 12.70
Options, weighted average exercise price, granted (in usd per share)	0
Options, weighted average exercise price, exercised (in usd per share)	14.46
Options, weighted average exercise price, forfeited (in usd per share)	22.83
Options, weighted average exercise price, end of period (in usd per share)	12.29	$ 12.70
Options, weighted average exercise price, exercisable (in usd per share)	$ 12.29
Weighted-Average Remaining Term
Options, outstanding, weighted average remaining term	2 years 5 months 19 days	3 years 18 days
Options, exercisable, weighted average remaining term	2 years 5 months 19 days
Restricted stock units
Shares
Outstanding at beginning of period (in shares)	1,085,628
Granted (in shares)	1,148,380
Vested (in shares)	(195,609)
Forfeited and canceled (in shares)	(308,984)
Outstanding at end of period (in shares)	1,729,415	1,085,628
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in usd per share)	$ 68.24
Granted (in usd per share)	50.85
Vested (in usd per share)	65.62
Forfeited and canceled (in usd per share)	72.90
Outstanding at end of period (in usd per share)	$ 56.17	$ 68.24
Performance-based restricted stock units
Shares
Outstanding at beginning of period (in shares)	1,036,925
Granted (in shares)	1,030,368
Vested (in shares)	(407,245)
Forfeited and canceled (in shares)	(75,783)
Outstanding at end of period (in shares)	1,584,265	1,036,925
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in usd per share)	$ 43.51
Granted (in usd per share)	15.93
Vested (in usd per share)	30.40
Forfeited and canceled (in usd per share)	35.21
Outstanding at end of period (in usd per share)	$ 29.35	$ 43.51
Cash-settled performance-based restricted stock units
Shares
Outstanding at beginning of period (in shares)	753,276
Granted (in shares)	0
Vested (in shares)	(317,949)
Forfeited and canceled (in shares)	0
Outstanding at end of period (in shares)	435,327	753,276

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).