Incentive Plan - Summary of Non-Vested Stock Units (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Number of Shares
Nonvested at beginning of period (in shares) | shares	539,606
Granted during period (in shares) | shares	860,402
Vested during period (in shares) | shares	(2,698)
Forfeited during period (in shares) | shares	(2,698)
Nonvested at end of period (in shares) | shares	1,394,612
Weighted Average Grant Date Fair Value Per Share
Nonvested at beginning of period (dollars per share) | $ / shares	$ 36.55
Granted during period (dollars per share) | $ / shares	41.37
Vested during period (dollars per share) | $ / shares	36.55
Forfeited during period (dollars per share) | $ / shares	36.55
Nonvested at end of period (dollars per share) | $ / shares	$ 39.53