Stockholders' Equity and Equity Compensation - Summary of Deferred Stock Unit Activity (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	1,501,021
Outstanding, ending balance (in shares) | shares	1,499,011
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 18.78
Outstanding, ending balance (in dollars per share) | $ / shares	$ 19.34
Deferred Stock Units
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	253,445
Awarded (in shares) | shares	45,042
Distributed (in shares) | shares	(30,559)
Outstanding, ending balance (in shares) | shares	267,928
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 19.93
Awarded (in dollars per share) | $ / shares	23.53
Distributed (in dollars per share) | $ / shares	23.57
Outstanding, ending balance (in dollars per share) | $ / shares	$ 20.12