Stock-Based Compensation - Summary Of Changes In CSEs Outstanding (Details) - Common stock equivalents	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Base fee percentage (up to)	50.00%
Common Stock Equivalents (CSEs) [Roll Forward]
Outstanding at December 31, 2017 (in shares) | shares	110,013
Granted (in shares) | shares	1,624
Converted to common shares upon grant (in shares) | shares	(998)
Outstanding at March 31, 2018 (in shares) | shares	110,639
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at December 31, 2017 (in dollars per share) | $ / shares	$ 23.19
Granted (in dollars per share) | $ / shares	116.06
Converted to common shares upon grant (in dollars per share) | $ / shares	124.94
Outstanding at March 31, 2018 (in dollars per share) | $ / shares	$ 23.59